Seal used to keep the body door , windows and other moving parts , and front and rear window , triangular windows , which are not part of the dynamic seal , seal shape and cross-section should be used to meet the requirements of different parts and different functions .
The purpose of the sealing strip :
1 , keep the car clean, weatherproof , dustproof , heat insulation, sound insulation ;
2, when the body is subjected to vibration and distortion ,colored cable ties the seal also cushion , shock absorption , keeping the role of glass ;
3 , on the edge of the transfer windows for decoration ;
Sealing strip material, natural rubber is often used to get up early , and later developed into ethylene, propylene rubber, nitrile rubber, synthetic rubber for the mainstream , but also the use of polyvinyl chloride resin. For fixed window edge portion of the front , rear , triangular windows, etc. , there is also a variety of paste forms ( such as direct bonding method or rubber band bonding method ) .
As the synthetic rubber foam should have a good performance , which requires :
1 , excellent weatherability ; 2, for coating with a non -polluting ; 3, a small residual deformation ; 4 , low water absorption ; 5 , can be maintained in good low temperature flexibility ; tamper seal tape 6 , having a heat resistance ; 7 , good wear resistance .
Door seal with the body is a more difficult position, sealing requirements are relatively strict, should be sealed part of a long , cross-sectional shape of the different parts of the seal , and the doors open and close frequently.
Door seals to achieve the basic shape has three sections : curved , compression type, complex . The seal is used in different parts of the shape is much more complex .
The arrangement of the door seals are: door -mounted ( fixed seal around the door ) , body -mounted ( seal fixed on the frame around the doorway ) , doors , body double mount ( around doors and openings around seals are installed on both sides ) .
Obviously , doors , body double sealing strip installed to improve the vehicle sealing, can vary according to the use of the site , made a variety of complex cross-sectional shape , in order to enhance the sealing effect, often set in the limousine three , four seals , before installing pillars and roof side beams parts quadruple seal structure . This multi -channel sealing crevices are generally arranged in the front door , in addition to having a sealing function, as well as car noise canceling effect.
high security bolt seals
high security bolt seals
2013年12月30日星期一
2013年12月23日星期一
Large windows and doors spring dust storm from the beginning
Spring wind, pervasive dust so that we stand it seems to rub home furniture re- ground , inevitably touched hand gray , so the spring anti-wind is a problem !
Important reason for many people at home , " eat dust " is the existence of a gap or window material aging , Pidian , damaged seals around doors and door bottom . Generally, door weight of a sand -proof ring . At present, many doors are steel security door, the door seal is good with the flatness of the door and sealing systems have a great relationship . If the door is not enough flatness or deformed , there will be sand quietly invasion. So when buying or replacing security door, choose a flat , excellent quality security door is critical .
For the old house , the anti-wind windows necessary to transform . There are four main forms:
1 , the installation of a new layer in the interior side of the window , which requires the original window openings have sufficient width countertops , new window frames sufficient thickness ;
2, with the original window frame as a new sub-frame windows , installing a new layer in the sub- frame windows .security ties This approach in a highly original window frame lower case selection, such as ordinary aluminum sliding window , otherwise it will affect the indoor lighting ;
3 , the transformation of the windows only open fan, replace the fan body and hardware to achieve the sealing effect , but it requires new windows and window profiles consistent with the original ;
4 , replacing the doors and windows sealed . According to the specifications of the doors and windows to select the matching model : D -type , P -, E- , I -type , such as , according to the doors of the main colors choose black , gray, white, brown , etc., and choose different specifications according to the size of the gap .
Finally, to remind everyone that if it is carried out a comprehensive reform of doors and windows , the best professional company to do . They will check the house wall structure , doors and windows of the structure and size, and then set a reasonable solution.ylon zip ties In addition , buy windows should also pay attention to the choice of plastic double-glazed windows with screens, windows sealing strip is particularly important because of its warmth , noise , anti-wind effects are better.
Important reason for many people at home , " eat dust " is the existence of a gap or window material aging , Pidian , damaged seals around doors and door bottom . Generally, door weight of a sand -proof ring . At present, many doors are steel security door, the door seal is good with the flatness of the door and sealing systems have a great relationship . If the door is not enough flatness or deformed , there will be sand quietly invasion. So when buying or replacing security door, choose a flat , excellent quality security door is critical .
For the old house , the anti-wind windows necessary to transform . There are four main forms:
1 , the installation of a new layer in the interior side of the window , which requires the original window openings have sufficient width countertops , new window frames sufficient thickness ;
2, with the original window frame as a new sub-frame windows , installing a new layer in the sub- frame windows .security ties This approach in a highly original window frame lower case selection, such as ordinary aluminum sliding window , otherwise it will affect the indoor lighting ;
3 , the transformation of the windows only open fan, replace the fan body and hardware to achieve the sealing effect , but it requires new windows and window profiles consistent with the original ;
4 , replacing the doors and windows sealed . According to the specifications of the doors and windows to select the matching model : D -type , P -, E- , I -type , such as , according to the doors of the main colors choose black , gray, white, brown , etc., and choose different specifications according to the size of the gap .
Finally, to remind everyone that if it is carried out a comprehensive reform of doors and windows , the best professional company to do . They will check the house wall structure , doors and windows of the structure and size, and then set a reasonable solution.ylon zip ties In addition , buy windows should also pay attention to the choice of plastic double-glazed windows with screens, windows sealing strip is particularly important because of its warmth , noise , anti-wind effects are better.
2013年12月16日星期一
Cold winter, the car how to better " moisturizer " mean ?
Now most of the northern region has entered the winter . People must be kept wet , the car also have to "moisture ." Face cold and dry , the most delicate parts of the car , including leather interior compartments , seats, the whole car and tire rubber seal materials , these tender parts in a dry environment easy to aging , wrinkling and even cracking, barrier security seals but just need a little aids plus your love, the problem is easily solved.
Leather interior , seat just like human skin , these leather products inside in a dry environment at once too much water loss will wrinkle even cracking. Cracks can restore people 's lips , really want to wait until the leather seats cracks may not be able to remedy it! Another problem is the treatment of these frequent contacts and body parts are not able to use oil-based protective agent - who are willing to sit in a chair beneath the greasy ass ? At this point we need to use leather conservation wax. In fact, this leather sofa in home care are also commonly used . It not only has a strong cleansing effect it clean , leather components can also keep up to one month moisturizing effect yet.
A large number of vehicles on the rubber seal is perhaps the most easily overlooked place. They shoulder a great responsibility for the vehicle waterproof, soundproof , but they are also vulnerable , prolonged exposure to air and low humidity will cause them to premature aging. Once the seal cracks on the car 's aging water, noise will have a huge impact . The same tire rubber material is also very fragile, dry environment in the long rubber material easily tire aging , and aging badly damaged once the tire wall , even if the tire tread is also deep there is no way to continue using it. Natural rubber parts for these moisturizing products also emerged , the market for sale is called " tire treasure" of the rubber material and maintenance agents , is dedicated to moisture supplies rubber components , its main function is to nourish , repair damaged rubber seal and tires ,tamper evident tapes slowing aging , and it is also in the maintenance of the same coating, when the car's four "feet" after a maintenance shiny black , you will find that your car is more than ever "handsome " was.
Leather interior , seat just like human skin , these leather products inside in a dry environment at once too much water loss will wrinkle even cracking. Cracks can restore people 's lips , really want to wait until the leather seats cracks may not be able to remedy it! Another problem is the treatment of these frequent contacts and body parts are not able to use oil-based protective agent - who are willing to sit in a chair beneath the greasy ass ? At this point we need to use leather conservation wax. In fact, this leather sofa in home care are also commonly used . It not only has a strong cleansing effect it clean , leather components can also keep up to one month moisturizing effect yet.
A large number of vehicles on the rubber seal is perhaps the most easily overlooked place. They shoulder a great responsibility for the vehicle waterproof, soundproof , but they are also vulnerable , prolonged exposure to air and low humidity will cause them to premature aging. Once the seal cracks on the car 's aging water, noise will have a huge impact . The same tire rubber material is also very fragile, dry environment in the long rubber material easily tire aging , and aging badly damaged once the tire wall , even if the tire tread is also deep there is no way to continue using it. Natural rubber parts for these moisturizing products also emerged , the market for sale is called " tire treasure" of the rubber material and maintenance agents , is dedicated to moisture supplies rubber components , its main function is to nourish , repair damaged rubber seal and tires ,tamper evident tapes slowing aging , and it is also in the maintenance of the same coating, when the car's four "feet" after a maintenance shiny black , you will find that your car is more than ever "handsome " was.
Rubber seal off how do
Glass installation loose rubber seal off how to do? Glass installation is not centered, glass sash gap with uneven rubber seal is not close to the glass and window frames, installation is not flat. Hand knock glass, loose sound.
The reason for this situation:
1 When installing the glass did not clear the debris inside the slot, and the slot right in the glass.
2 glass with glass notch uneven gaps, seals and glass tank exposed, protruding notch glass,indicative seals hand sealing tape can be easily pulled off.
3 in the corner of the rubber is not disconnected, not injection of glue.
Corrective measures are:
1 carefully before installing the glass to clear the debris inside the slot, such as mortar, brick dust, wood, etc., should be carefully placed on the glass, ensuring that both sides of the gap is uniform, and timely than the regular fixed to prevent collisions shift deviation notch center.
2. Rubber seal can not pull too tight, cutting length than the length of the long assembly 2O-3Omm. When installing the mosaic in place, flat surfaces, and glass notch in close contact, so that the glass surrounding the force evenly. In the corner of the rubber should be beveled off and disconnect the injection of glue at the firm.
3 When caulk sealant fixed glass, you should use rubber or rubber block and choked the glass, leaving a gap of plastic injection, plastic injection depth should not be less than 5mm, before the glue curing, the glass should be kept free from vibration.nylon cable tie Installation is not centered, glass frames with uneven gaps, not close to the glass sealing strips and window frames, installation is not flat. Hand knock glass, loose sound.
The reason for this situation:
1 When installing the glass did not clear the debris inside the slot, and the slot right in the glass.
2 glass with glass notch uneven gaps, seals and glass tank exposed, protruding notch glass,indicative seals hand sealing tape can be easily pulled off.
3 in the corner of the rubber is not disconnected, not injection of glue.
Corrective measures are:
1 carefully before installing the glass to clear the debris inside the slot, such as mortar, brick dust, wood, etc., should be carefully placed on the glass, ensuring that both sides of the gap is uniform, and timely than the regular fixed to prevent collisions shift deviation notch center.
2. Rubber seal can not pull too tight, cutting length than the length of the long assembly 2O-3Omm. When installing the mosaic in place, flat surfaces, and glass notch in close contact, so that the glass surrounding the force evenly. In the corner of the rubber should be beveled off and disconnect the injection of glue at the firm.
3 When caulk sealant fixed glass, you should use rubber or rubber block and choked the glass, leaving a gap of plastic injection, plastic injection depth should not be less than 5mm, before the glue curing, the glass should be kept free from vibration.nylon cable tie Installation is not centered, glass frames with uneven gaps, not close to the glass sealing strips and window frames, installation is not flat. Hand knock glass, loose sound.
2013年12月9日星期一
How to correctly apply seals
Proper application of seals can improve the safety of work :
1 person has no right to sealed properly applied closure device in the vehicle Guankou unsealed .
(2) All drivers are not be altered by seals, wire seals such as the discovery of internal abnormalities , must live sealed, signed off by the client . While reporting to management personnel , business dedicated to confirm
3 the driver of the vehicle at the scene only Guankou sealed.
(4) Other personnel , such as work needs to be unsealed , shall notify customers unsealed and sealed together .
5 When Guankou device sealed , must be clearly visible logo and number on seals .
6 sealed after the first wire length should not exceed 1.5cm, cut off the excess wire rope shall be treated with diagonal pliers, pull out the head hole wire spread .
7 logo and number font is unclear,cable sealing the responsible person shall promptly report to the users , the timely replacement .
1 person has no right to sealed properly applied closure device in the vehicle Guankou unsealed .
(2) All drivers are not be altered by seals, wire seals such as the discovery of internal abnormalities , must live sealed, signed off by the client . While reporting to management personnel , business dedicated to confirm
3 the driver of the vehicle at the scene only Guankou sealed.
(4) Other personnel , such as work needs to be unsealed , shall notify customers unsealed and sealed together .
5 When Guankou device sealed , must be clearly visible logo and number on seals .
6 sealed after the first wire length should not exceed 1.5cm, cut off the excess wire rope shall be treated with diagonal pliers, pull out the head hole wire spread .
7 logo and number font is unclear,cable sealing the responsible person shall promptly report to the users , the timely replacement .
2013年12月2日星期一
How to identify the merits of the spiral protective sleeve ?
1 surface appearance
Plastic protective sleeve surface smooth, no lack of material , cracks, damage , burrs , no blistering and uneven ,truck security seals no impurities, variegated and other phenomena was of high quality ; contrary, was of poor quality , substandard .
2 Hardness
Qualified quality spiral protective cover hardness is generally 85-90 degrees Shore hardness is below 85 degrees or above 90 degrees do not meet the requirements. Hardness is too low , you can not play the internal product protection , binding effect ; excessive hardness , when used at low temperatures , protective sleeve prone to embrittlement, 1% to 5 % of the products can not meet the requirements, the spiral protective sleeve the protective effect of internal product is greatly reduced.
3 . Resistance to high temperature
Qualified quality spiral protective cover should have good resistance to high temperature performance. Identification of the user using the following method : turn the screw placed under protective cover 80 ℃ ambient 1 hour , 0.5 hours under room temperature under -40 ℃ environment for 1 hour at room temperature environment 0.5 hours , do it five cycles. Observation, if the spiral protective cover without cracking, sticky, depression occurred, compared with high-quality ; Conversely, if the spiral protective cover cracking , deformation, etc. One sticky or depression phenomena , the protective sleeve is inferior , not qualified.
4 oil resistance
Qualified quality spiral protective sleeve has good oil resistance. The protective sleeve can be soaked in a mixture of the coil 70 # gasoline and 10 percent toluene for 5 minutes , without discoloration phenomenon tacky compared to high- pass ; contrary, discolored , sticky phenomenon , the protective sleeve is poor , failed.
5. Wear
Qualified quality spiral protective sleeve has good wear resistance.
6 tensile strength , impact strength
High- pass coil protection cover has good tensile strength and impact strength, tensile strength at room temperature is generally 25-30Mpa; generally impact strength ( notched ) at room temperature was 35KJ/M2, -40 ℃ / 24h to 5KJ / M, impact strength ( unnotched ) fixed length plastic strap seal, continuously.
7 anti-UV
Spiral protective sleeve has good UV resistance . Protective sleeve black spiral columns must be better than carbon black production , to enhance UV resistance spiral protective sleeve .
8. Antistatic
Spiral protective sleeve is mainly used excavators, loaders, rollers pavers , forklifts , cranes, pumping machinery , outside the protection of cables and other construction machinery and injection molding machine equipment . Underground, dry environment when the job should be considered a strong choice spiral antistatic protective sleeve . Antistatic properties to enhance the internal hydraulic pipe fittings and other products , in a variety of harsh environments of the hydraulic tube play better security role !
Plastic protective sleeve surface smooth, no lack of material , cracks, damage , burrs , no blistering and uneven ,truck security seals no impurities, variegated and other phenomena was of high quality ; contrary, was of poor quality , substandard .
2 Hardness
Qualified quality spiral protective cover hardness is generally 85-90 degrees Shore hardness is below 85 degrees or above 90 degrees do not meet the requirements. Hardness is too low , you can not play the internal product protection , binding effect ; excessive hardness , when used at low temperatures , protective sleeve prone to embrittlement, 1% to 5 % of the products can not meet the requirements, the spiral protective sleeve the protective effect of internal product is greatly reduced.
3 . Resistance to high temperature
Qualified quality spiral protective cover should have good resistance to high temperature performance. Identification of the user using the following method : turn the screw placed under protective cover 80 ℃ ambient 1 hour , 0.5 hours under room temperature under -40 ℃ environment for 1 hour at room temperature environment 0.5 hours , do it five cycles. Observation, if the spiral protective cover without cracking, sticky, depression occurred, compared with high-quality ; Conversely, if the spiral protective cover cracking , deformation, etc. One sticky or depression phenomena , the protective sleeve is inferior , not qualified.
4 oil resistance
Qualified quality spiral protective sleeve has good oil resistance. The protective sleeve can be soaked in a mixture of the coil 70 # gasoline and 10 percent toluene for 5 minutes , without discoloration phenomenon tacky compared to high- pass ; contrary, discolored , sticky phenomenon , the protective sleeve is poor , failed.
5. Wear
Qualified quality spiral protective sleeve has good wear resistance.
6 tensile strength , impact strength
High- pass coil protection cover has good tensile strength and impact strength, tensile strength at room temperature is generally 25-30Mpa; generally impact strength ( notched ) at room temperature was 35KJ/M2, -40 ℃ / 24h to 5KJ / M, impact strength ( unnotched ) fixed length plastic strap seal, continuously.
7 anti-UV
Spiral protective sleeve has good UV resistance . Protective sleeve black spiral columns must be better than carbon black production , to enhance UV resistance spiral protective sleeve .
8. Antistatic
Spiral protective sleeve is mainly used excavators, loaders, rollers pavers , forklifts , cranes, pumping machinery , outside the protection of cables and other construction machinery and injection molding machine equipment . Underground, dry environment when the job should be considered a strong choice spiral antistatic protective sleeve . Antistatic properties to enhance the internal hydraulic pipe fittings and other products , in a variety of harsh environments of the hydraulic tube play better security role !
Automotive sealing Development
For a long time , the vehicle must have a seal requires three functions : connecting , sealing and decorative. With the advancement of technology, the development of the automotive industry , especially in emerging new materials , environmental protection awareness of the car , comfort , safety, aesthetics have become increasingly demanding , the previous three functions for automotive sealing requirements are constantly introduce new and improved. To meet passenger vehicle performance and grades increasing needs, are from Applied Materials seals for passenger cars , product structure and production technology and other aspects of analysis, research trends strip door seal industry
Development of a passenger seal Review
Before the 1980s , because of the limitations of science and technology level , almost all automotive seals, mostly connected only considered to meet the performance and some sealing performance, with little regard for decorative, safety and comfort. Therefore , when the seal only consider using buses connect many aspects , such as the front and rear windscreens , side windows , door seal ; structure is very simple , mostly single types of plastic , one end connected to the body , one end connected to glass ; the material is natural rubber or styrene-butadiene rubber , plastics ( mainly modified PV C) based. Although such a seal to meet the connectivity and some sealing performance, but other properties such as elasticity , waterproof, noise canceling , isolation , dust , heat , weather , ozone resistance, anti-aging , etc. are poor, let alone the aesthetics and comfort . Due to the performance limitations of the material itself , the life of the car with the seal only 3 to 5 years, can not match the life of passenger cars ; color is also relatively simple ( almost entirely of black rubber ) , not to mention decorative and beautiful of it. Doors , body , luggage compartment seal are poor, large interior noise , dust, water is also very poor. The late 1980s, with the continuous improvement of passenger grade , with a seal on the passenger 's requirements have been increased .
Two seals currently used bus status
From the 1980s to the present , the automotive parts industry, the comprehensive performance requirements increasing, of course, the seal industry has great development.
( 1 ) before sealing the product mix has changed a lot . The original single types of plastic adhesive to now two types ( ie, dense or dense rubber and sponge rubber compound ) , three composite materials ( ie dense rubber, sponge rubber and steel or nylon composite skeleton ) , four composite materials ( i.e. dense rubber, sponge rubber or nylon and steel frame , four composite flocking material ) . Natural rubber ( or styrene ) and plastic , using a synthetic rubber EPDM (EPDM).
Application ( 2 ) the development of a new material . Abandoned strength , heat resistance, weather resistance, aging resistance are poor natural rubber ( SBR or ) and plastic , using a synthetic rubber EPDM (EPDM). E PDM has excellent heat resistance, weather resistance, ozone resistance , and its main physical properties are shown in Table 1. Due to the excellent characteristics E PDM , so the recent decades of sustained growth in sales volume .
( 3 ) Production farewell pure steam autoclave curing rubber extrusion original production process, using a more advanced multi- head extrusion microwave curing production process, as well as secondary processing injection molding process .
Obviously, the primary seal is the most basic function is to seal needs water, every noise and dust . Indeed , the sealing effect can be further improved by improving the design . Now anti-friction material requirements are also increasing, so that the sealing performance can be maintained for longer , but also to reduce the damage during the original installation . The main role of the seal is to make the car as much as possible with the outside world, to maximize driver and passenger comfort . It should be said , and now the seal connecting , sealing , decorative, security, and so have a greater degree of improvement over the previous twenty- 1980s, but in the decorative, environmental aspects are still some gaps .
3 passenger trends sealing strip
The rapid development of the automotive industry , the performance of the car with a variety of seal put forward higher requirements. Development of new materials, new technology applications of science and technology for the development of the seal industry provides a space for development. Requirements for seals not only stay on the connection , sealing, decorative three functions, the car 's environmentally friendly, safe , comfortable and beautiful and so put forward new demands. This requires the selection of material from the sealing strip , structural improvements, the selection of the manufacturing process required to continue to improve .
( 1 ) From the choice of materials , not just stay on the E PDM applications. Molding process is relatively simple thermoplastic elastomers : T PV ( thermoplastic elastomer vaporization ), TPE ( thermoplastic elastomer ), T PO ( thermoplastic olefin ) ,high security seal etc. has been widely used in some areas. They have strong coloring , compound and recyclability good , but also to meet environmental requirements. Physical properties of thermoplastic elastomer in Table 1, the following advantages : excellent flex fatigue life ; temperature ; high impact strength ; density ; excellent chemical resistance and weathering resistance ; excellent electrical properties ; high high tear and abrasion resistance ; colorability ; renewable ; able to co-injection molding and extrusion pressure and total polyolefin ; low tensile and compression set .
( 2 ) structural improvements : The outer surface of the composite in harmony with the vehicle interior materials of different colors , such as color E PDM, colored thermoplastic elastomer ; using surface coating wear and lubrication materials instead of the original flocking material ; application various smooth surface coating , matte or four colored composite material .
( 3) Process Improvement : full speed with pre- shaped hot air vulcanization ordinary microwave hot air vulcanization process + + + , greatly improving the surface quality and production efficiency vulcanized sealing strips ; cancel the original molding process , replacing various secondary injection molding process , both to improve the efficiency and quality improvements ; online instead of the original hand- spraying spraying .
4 Conclusion
In short , with the continuous improvement of quality cars , buses seal performance requirements have been increased . Structure is reasonable, humane design , production process flow , automation, product safety , environmental protection metal security seals, recyclability , matching aesthetics, diversity is important to consider the performance of automotive sealing .
Development of a passenger seal Review
Before the 1980s , because of the limitations of science and technology level , almost all automotive seals, mostly connected only considered to meet the performance and some sealing performance, with little regard for decorative, safety and comfort. Therefore , when the seal only consider using buses connect many aspects , such as the front and rear windscreens , side windows , door seal ; structure is very simple , mostly single types of plastic , one end connected to the body , one end connected to glass ; the material is natural rubber or styrene-butadiene rubber , plastics ( mainly modified PV C) based. Although such a seal to meet the connectivity and some sealing performance, but other properties such as elasticity , waterproof, noise canceling , isolation , dust , heat , weather , ozone resistance, anti-aging , etc. are poor, let alone the aesthetics and comfort . Due to the performance limitations of the material itself , the life of the car with the seal only 3 to 5 years, can not match the life of passenger cars ; color is also relatively simple ( almost entirely of black rubber ) , not to mention decorative and beautiful of it. Doors , body , luggage compartment seal are poor, large interior noise , dust, water is also very poor. The late 1980s, with the continuous improvement of passenger grade , with a seal on the passenger 's requirements have been increased .
Two seals currently used bus status
From the 1980s to the present , the automotive parts industry, the comprehensive performance requirements increasing, of course, the seal industry has great development.
( 1 ) before sealing the product mix has changed a lot . The original single types of plastic adhesive to now two types ( ie, dense or dense rubber and sponge rubber compound ) , three composite materials ( ie dense rubber, sponge rubber and steel or nylon composite skeleton ) , four composite materials ( i.e. dense rubber, sponge rubber or nylon and steel frame , four composite flocking material ) . Natural rubber ( or styrene ) and plastic , using a synthetic rubber EPDM (EPDM).
Application ( 2 ) the development of a new material . Abandoned strength , heat resistance, weather resistance, aging resistance are poor natural rubber ( SBR or ) and plastic , using a synthetic rubber EPDM (EPDM). E PDM has excellent heat resistance, weather resistance, ozone resistance , and its main physical properties are shown in Table 1. Due to the excellent characteristics E PDM , so the recent decades of sustained growth in sales volume .
( 3 ) Production farewell pure steam autoclave curing rubber extrusion original production process, using a more advanced multi- head extrusion microwave curing production process, as well as secondary processing injection molding process .
Obviously, the primary seal is the most basic function is to seal needs water, every noise and dust . Indeed , the sealing effect can be further improved by improving the design . Now anti-friction material requirements are also increasing, so that the sealing performance can be maintained for longer , but also to reduce the damage during the original installation . The main role of the seal is to make the car as much as possible with the outside world, to maximize driver and passenger comfort . It should be said , and now the seal connecting , sealing , decorative, security, and so have a greater degree of improvement over the previous twenty- 1980s, but in the decorative, environmental aspects are still some gaps .
3 passenger trends sealing strip
The rapid development of the automotive industry , the performance of the car with a variety of seal put forward higher requirements. Development of new materials, new technology applications of science and technology for the development of the seal industry provides a space for development. Requirements for seals not only stay on the connection , sealing, decorative three functions, the car 's environmentally friendly, safe , comfortable and beautiful and so put forward new demands. This requires the selection of material from the sealing strip , structural improvements, the selection of the manufacturing process required to continue to improve .
( 1 ) From the choice of materials , not just stay on the E PDM applications. Molding process is relatively simple thermoplastic elastomers : T PV ( thermoplastic elastomer vaporization ), TPE ( thermoplastic elastomer ), T PO ( thermoplastic olefin ) ,high security seal etc. has been widely used in some areas. They have strong coloring , compound and recyclability good , but also to meet environmental requirements. Physical properties of thermoplastic elastomer in Table 1, the following advantages : excellent flex fatigue life ; temperature ; high impact strength ; density ; excellent chemical resistance and weathering resistance ; excellent electrical properties ; high high tear and abrasion resistance ; colorability ; renewable ; able to co-injection molding and extrusion pressure and total polyolefin ; low tensile and compression set .
( 2 ) structural improvements : The outer surface of the composite in harmony with the vehicle interior materials of different colors , such as color E PDM, colored thermoplastic elastomer ; using surface coating wear and lubrication materials instead of the original flocking material ; application various smooth surface coating , matte or four colored composite material .
( 3) Process Improvement : full speed with pre- shaped hot air vulcanization ordinary microwave hot air vulcanization process + + + , greatly improving the surface quality and production efficiency vulcanized sealing strips ; cancel the original molding process , replacing various secondary injection molding process , both to improve the efficiency and quality improvements ; online instead of the original hand- spraying spraying .
4 Conclusion
In short , with the continuous improvement of quality cars , buses seal performance requirements have been increased . Structure is reasonable, humane design , production process flow , automation, product safety , environmental protection metal security seals, recyclability , matching aesthetics, diversity is important to consider the performance of automotive sealing .
2013年11月22日星期五
Advantages elastic soft seal gate valve
Flexible soft sealing gate advantages:
1 small, lightweight, easy installation and maintenance, and can be mounted in any position.
2 simple and compact structure, plastic seal small operating torque, 90 degree rotation to open quickly.
3 linear flow characteristics tend to adjust better performance.
4 disc and stem-free pin connector structure, it is possible to overcome the internal leak.
5 seals can be replaced, and reliable sealing achieve bi-directional sealing.
6 disc spray coating according to user requirements, such as nylon or PTFE classes.
7 The valve can be designed flanged and wafer.
8 drive optional manual,security seals electric or pneumatic.
1 small, lightweight, easy installation and maintenance, and can be mounted in any position.
2 simple and compact structure, plastic seal small operating torque, 90 degree rotation to open quickly.
3 linear flow characteristics tend to adjust better performance.
4 disc and stem-free pin connector structure, it is possible to overcome the internal leak.
5 seals can be replaced, and reliable sealing achieve bi-directional sealing.
6 disc spray coating according to user requirements, such as nylon or PTFE classes.
7 The valve can be designed flanged and wafer.
8 drive optional manual,security seals electric or pneumatic.
The performance of the mechanical seal failure and the reasons
Mechanical seal failure in the operation of rotating equipment parts which, they would often wear the seal faces, thermal cracking, deformation, breakage, etc., will be the spring with a long relaxation, fracture and corrosion. Secondary seal cracks will appear, twisted and deformed, broken and so on.
Mechanical seal vibration, heat cause of the malfunction
During rotation of the device, causes the end face of the static ring bonded rough movement ring and seal chamber gap is too small, the runout caused by collision induced vibration. Sometimes, because of the seal faces resistance to corrosion and heat resistance poor or insufficient cooling or end during the installation folder particulate impurities can cause mechanical vibration and heat sealed.
Reasons for failure of the mechanical seal media leaks
(1) Static pressure leak test. Because of the mechanical seal is not careful when installing, tend to make the seal faces are bruised, deformation, damage, clean up without a net, there are the granular impurities, or due to loose screws, no compression gland, machinery, equipment, precision is not enough , so that the sealing surface is not completely fit, will cause media leaks. If it is missing sleeve bushing seal assembly is pressed or not enough compression or damage. (2) periodic or episodic leakage. plastic strap seal Mechanical seal rotor assembly periodic vibration, axial runout too, can cause leakage. Mechanical seal sealing surface pressure to have a certain ratio, so as to function as a sealing, mechanical seal which requires to have a certain amount of compression of the spring, a thrust force to the seal faces, so that the rotating sealing surface sealing up the required ratio pressure. To guarantee this one than the pressure required mechanical shaft seal can not have too much channeling amount, generally to ensure that within 0.25mm. However, in practical designs, the design is unreasonable, the shaft tends to produce a large amount of channeling, the use of mechanical seals are very unfavorable. (3) recurrent mechanical seal leakage. Frequent cause of mechanical seal leaks in many aspects. Firstly, since the seal faces recurring defects caused by the leak. The second aspect is secondary seal caused by recurring leaks. Third, the spring leakage defects. Other aspects include leakage rotor vibration caused by bad driving, and thrust tight or loose parts quality caused leaks, leaks caused by mechanical seal auxiliary organizations, the media due to problems caused by recurrent leakage. (4) mechanical seal vibration is too large.plastic strap seals Mechanical seal vibration is too large, resulting in loss of seal. But the mechanical seal is often the cause of vibration larger reason than just mechanical seal itself, other parts of the pump is also the root cause of vibration, such as shaft design is unreasonable, because of processing, lack of precision bearings, parallel coupling poor, radial force and other reasons
Mechanical seal vibration, heat cause of the malfunction
During rotation of the device, causes the end face of the static ring bonded rough movement ring and seal chamber gap is too small, the runout caused by collision induced vibration. Sometimes, because of the seal faces resistance to corrosion and heat resistance poor or insufficient cooling or end during the installation folder particulate impurities can cause mechanical vibration and heat sealed.
Reasons for failure of the mechanical seal media leaks
(1) Static pressure leak test. Because of the mechanical seal is not careful when installing, tend to make the seal faces are bruised, deformation, damage, clean up without a net, there are the granular impurities, or due to loose screws, no compression gland, machinery, equipment, precision is not enough , so that the sealing surface is not completely fit, will cause media leaks. If it is missing sleeve bushing seal assembly is pressed or not enough compression or damage. (2) periodic or episodic leakage. plastic strap seal Mechanical seal rotor assembly periodic vibration, axial runout too, can cause leakage. Mechanical seal sealing surface pressure to have a certain ratio, so as to function as a sealing, mechanical seal which requires to have a certain amount of compression of the spring, a thrust force to the seal faces, so that the rotating sealing surface sealing up the required ratio pressure. To guarantee this one than the pressure required mechanical shaft seal can not have too much channeling amount, generally to ensure that within 0.25mm. However, in practical designs, the design is unreasonable, the shaft tends to produce a large amount of channeling, the use of mechanical seals are very unfavorable. (3) recurrent mechanical seal leakage. Frequent cause of mechanical seal leaks in many aspects. Firstly, since the seal faces recurring defects caused by the leak. The second aspect is secondary seal caused by recurring leaks. Third, the spring leakage defects. Other aspects include leakage rotor vibration caused by bad driving, and thrust tight or loose parts quality caused leaks, leaks caused by mechanical seal auxiliary organizations, the media due to problems caused by recurrent leakage. (4) mechanical seal vibration is too large.plastic strap seals Mechanical seal vibration is too large, resulting in loss of seal. But the mechanical seal is often the cause of vibration larger reason than just mechanical seal itself, other parts of the pump is also the root cause of vibration, such as shaft design is unreasonable, because of processing, lack of precision bearings, parallel coupling poor, radial force and other reasons
2013年11月5日星期二
Introduction pump mechanical seal standard
This paper summarizes the mechanical seal on the pump standards, including marine mechanical shaft seals, pump mechanical seal alkali, acid pumps with mechanical seals, mechanical seals for pumps and other industry standards.
GB / T 5661-2004 suction centrifugal pumps mechanical seals and for soft packing cavity dimensions
GB / T 5661-2004 suction centrifugal pumps mechanical seals and for soft packing cavity dimensions including compliance with the provisions of GB / T 5662, including horizontal axial suction centrifugal pump of the cascading balanced mechanical seals, suitable for direct axis The mechanical seal and soft packing seal cavity size.
GB / T 3345-88 marine mechanical shaft seal
GB / T 3345-88 marine mechanical shaft seal provides ships with a built-in single shaft seal Unbalanced and balanced built single-end mechanical seal product classification, technical requirements, test methods, inspection rules, marking and packaging .
GB / T 3346-88 marine variable pressure pump mechanical seal
GB / T 3346-88 marine variable pressure pump mechanical seal provides marine variable pressure pump mechanical seal product classification, technical requirements, and test methods, inspection rules, packaging and assurance.
JB / T 7371-1994 alkali pump mechanical seal
JB / T 7371-1994 alkali pump mechanical seal provides alkali pump mechanical seal type, parameters, main dimensions, model species representation, technical requirements, testing and test methods, installation requirements and so on.
JB / T 7371-1994 alkali pump mechanical seal for alkali pump mechanical seal
JB / T 7372-1994 acid pump mechanical seal
JB / T 7372-1994 standard acid pump mechanical seal provides the acid pump mechanical seal with the basic version, the main dimensions, parameters, material, model representation, technical requirements and so on.
JB / T 7372-1994 acid pump mechanical seal for acid pump mechanical seal.
JB / T 1472-1994 pump mechanical seal
JB / T 1472-1994 pump mechanical seal pump mechanical seal provides the basic type, main dimensions, model representation, technical requirements, etc.,
JB / T 1472-1994 pump mechanical seal for rotary mechanical seals and other similar mechanical rotary shaft seal.
JB / T 6614-1993 boiler feed water pump mechanical seal technology
JB / T 6614-1993 boiler feed water pump mechanical truck security seals technology provides for boiler feed water pump mechanical seal of the main types, that is, requirements, testing and test methods, inspection rules and other requirements.
JB / T 6614-1993 boiler feed water pump mechanical seal technology for boiler water temperature no higher than 260 ° C the boiler feed pump seals supporting the use of heavy machinery
JB / T 5966-1995 submersible pump mechanical seal
JB / T 5966-1995 submersible pump mechanical seal provides submersible pump mechanical seal type, parameters and main dimensions, model representation, technical requirements, test methods and inspection rules, installation and use requirements and so on.
JB / T 5966-1995 submersible pump mechanical seal for submersible pumps with mechanical seals.
HG / T 2478-1993 lined pump mechanical seal technology
HG / T 4114-2009 pulp pump mechanical seal technology provides a glass-lined pump mechanical seal design, manufacture, use, testing, marking and installation requirements.
HG / T 4114-2009 pulp pump mechanical luggage seals technology for seal chamber pressure 0 ~ 0.3MPa, Operating Temperature 0 ~ 70 ° C, the shaft speed is less than 3000r/min, 30 ~ 80mm shaft diameter of the bore glass pump mechanical seal (hereinafter referred to as mechanical seal)
HG / T 2100-2003 chlorine liquid ring pump mechanical seal
HG / T 2100-2003 chlorine liquid ring pump mechanical seal provides chlorine liquid ring pump mechanical seal structure type, technical requirements, testing, installation and use.
GB / T 5661-2004 suction centrifugal pumps mechanical seals and for soft packing cavity dimensions
GB / T 5661-2004 suction centrifugal pumps mechanical seals and for soft packing cavity dimensions including compliance with the provisions of GB / T 5662, including horizontal axial suction centrifugal pump of the cascading balanced mechanical seals, suitable for direct axis The mechanical seal and soft packing seal cavity size.
GB / T 3345-88 marine mechanical shaft seal
GB / T 3345-88 marine mechanical shaft seal provides ships with a built-in single shaft seal Unbalanced and balanced built single-end mechanical seal product classification, technical requirements, test methods, inspection rules, marking and packaging .
GB / T 3346-88 marine variable pressure pump mechanical seal
GB / T 3346-88 marine variable pressure pump mechanical seal provides marine variable pressure pump mechanical seal product classification, technical requirements, and test methods, inspection rules, packaging and assurance.
JB / T 7371-1994 alkali pump mechanical seal
JB / T 7371-1994 alkali pump mechanical seal provides alkali pump mechanical seal type, parameters, main dimensions, model species representation, technical requirements, testing and test methods, installation requirements and so on.
JB / T 7371-1994 alkali pump mechanical seal for alkali pump mechanical seal
JB / T 7372-1994 acid pump mechanical seal
JB / T 7372-1994 standard acid pump mechanical seal provides the acid pump mechanical seal with the basic version, the main dimensions, parameters, material, model representation, technical requirements and so on.
JB / T 7372-1994 acid pump mechanical seal for acid pump mechanical seal.
JB / T 1472-1994 pump mechanical seal
JB / T 1472-1994 pump mechanical seal pump mechanical seal provides the basic type, main dimensions, model representation, technical requirements, etc.,
JB / T 1472-1994 pump mechanical seal for rotary mechanical seals and other similar mechanical rotary shaft seal.
JB / T 6614-1993 boiler feed water pump mechanical seal technology
JB / T 6614-1993 boiler feed water pump mechanical truck security seals technology provides for boiler feed water pump mechanical seal of the main types, that is, requirements, testing and test methods, inspection rules and other requirements.
JB / T 6614-1993 boiler feed water pump mechanical seal technology for boiler water temperature no higher than 260 ° C the boiler feed pump seals supporting the use of heavy machinery
JB / T 5966-1995 submersible pump mechanical seal
JB / T 5966-1995 submersible pump mechanical seal provides submersible pump mechanical seal type, parameters and main dimensions, model representation, technical requirements, test methods and inspection rules, installation and use requirements and so on.
JB / T 5966-1995 submersible pump mechanical seal for submersible pumps with mechanical seals.
HG / T 2478-1993 lined pump mechanical seal technology
HG / T 4114-2009 pulp pump mechanical seal technology provides a glass-lined pump mechanical seal design, manufacture, use, testing, marking and installation requirements.
HG / T 4114-2009 pulp pump mechanical luggage seals technology for seal chamber pressure 0 ~ 0.3MPa, Operating Temperature 0 ~ 70 ° C, the shaft speed is less than 3000r/min, 30 ~ 80mm shaft diameter of the bore glass pump mechanical seal (hereinafter referred to as mechanical seal)
HG / T 2100-2003 chlorine liquid ring pump mechanical seal
HG / T 2100-2003 chlorine liquid ring pump mechanical seal provides chlorine liquid ring pump mechanical seal structure type, technical requirements, testing, installation and use.
Small caliber Ball Valve Product Knowledge
An Overview
Ball in the petroleum, chemical, metallurgical and urban central heating and other industries has been widely used. But the sealing of PTFE polymer material of the ball, can not be used for temperature greater than 280 ℃ or transport medium was small granular condition. The materials for the sealing of metal hard seal ball valve, ball rotation will result in different structures of circumstances. Resilient sealing structure such as a metal seat, the elastic valve seat and does not form a gap between the spheres, so its great friction. Metal floating seat seal structure between its floating seat and valve seal is not easy. Combination ball softened sealing structure, because spare parts and more complex structure, increasing the difficulty of processing and manufacturing costs, especially small diameter seal valve, this structure is clearly not applicable. After repeated analysis and testing, and the help of CAD, successfully developed Q47H cam eccentric single seal valve seat fixed.
2 Work
Single eccentric cam ball seat valve center line offset with respect to the center line a, b, the valve seat sealing surface eccentric b. When the valve stem clockwise about O 90 °, then the sphere also rotates 90 °, and in close agreement with the valve seat sealing surface when the friction between the sealing filler stem between torque and friction torque is greater than the medium pressure forming torque, the valve will reach a reliable cable marker ties. As the valve seal with eccentric cam structure, when the valve is opened, the ball quickly from the valve seat sealing surface. When the valve is closed, the ball and seat sealing surface anastomosis quickly. So as to achieve the opening torque is small, close tightly purposes.
Three structural features
Small-diameter valve body cavity narrow space, the usual structural design is not applicable. Therefore, the stem ends with a short axis and processed into flat, spherical tank and the upper and lower holes are flat, the hole for connecting the upper and lower stem play a fixed sphere, limiting the role of freedom sphere, while balance the body cavity with the pipeline between media pressure. And stem with flat groove, the torque transmitted from the handle.
4 manufacturing and processing
Sphere two hole concentricity and ball valve centerline relative to the centerline of the eccentric dimensional tolerances more stringent requirements, generally require boring or CNC machining. Before assembly seat sealing surface and the ball should be equipped with a decent research, and then placed in the closed position of the sphere, installing left valve, adjusting pads, tighten the screws, the static pressure irrigation does not leak, this valve can be guaranteed in a sealed test under plastic security seal .
5 Conclusion
Seal small diameter ball valve structure in accordance with the length of existing home and abroad, connection type and dimensions related standards, the valve is not only suitable for conveying gaseous or liquid-phase medium, but also for medium and a liquid-liquid mixed slurry mixed media. The valve is used in metallurgy, textile and oil industries, to good effect.
Ball in the petroleum, chemical, metallurgical and urban central heating and other industries has been widely used. But the sealing of PTFE polymer material of the ball, can not be used for temperature greater than 280 ℃ or transport medium was small granular condition. The materials for the sealing of metal hard seal ball valve, ball rotation will result in different structures of circumstances. Resilient sealing structure such as a metal seat, the elastic valve seat and does not form a gap between the spheres, so its great friction. Metal floating seat seal structure between its floating seat and valve seal is not easy. Combination ball softened sealing structure, because spare parts and more complex structure, increasing the difficulty of processing and manufacturing costs, especially small diameter seal valve, this structure is clearly not applicable. After repeated analysis and testing, and the help of CAD, successfully developed Q47H cam eccentric single seal valve seat fixed.
2 Work
Single eccentric cam ball seat valve center line offset with respect to the center line a, b, the valve seat sealing surface eccentric b. When the valve stem clockwise about O 90 °, then the sphere also rotates 90 °, and in close agreement with the valve seat sealing surface when the friction between the sealing filler stem between torque and friction torque is greater than the medium pressure forming torque, the valve will reach a reliable cable marker ties. As the valve seal with eccentric cam structure, when the valve is opened, the ball quickly from the valve seat sealing surface. When the valve is closed, the ball and seat sealing surface anastomosis quickly. So as to achieve the opening torque is small, close tightly purposes.
Three structural features
Small-diameter valve body cavity narrow space, the usual structural design is not applicable. Therefore, the stem ends with a short axis and processed into flat, spherical tank and the upper and lower holes are flat, the hole for connecting the upper and lower stem play a fixed sphere, limiting the role of freedom sphere, while balance the body cavity with the pipeline between media pressure. And stem with flat groove, the torque transmitted from the handle.
4 manufacturing and processing
Sphere two hole concentricity and ball valve centerline relative to the centerline of the eccentric dimensional tolerances more stringent requirements, generally require boring or CNC machining. Before assembly seat sealing surface and the ball should be equipped with a decent research, and then placed in the closed position of the sphere, installing left valve, adjusting pads, tighten the screws, the static pressure irrigation does not leak, this valve can be guaranteed in a sealed test under plastic security seal .
5 Conclusion
Seal small diameter ball valve structure in accordance with the length of existing home and abroad, connection type and dimensions related standards, the valve is not only suitable for conveying gaseous or liquid-phase medium, but also for medium and a liquid-liquid mixed slurry mixed media. The valve is used in metallurgy, textile and oil industries, to good effect.
2013年11月4日星期一
Common features of the application of self-adhesive materials
As a self-adhesive label printing material from the surface of its structure is composed of three parts , namely the surface materials, adhesives and backing paper . Label surface material selection must be based on the use of environmental labels and handling.
Then the sticker surface material is a positive acceptance printing graphics , and finally back to accept the adhesive is applied to the material on the pasted object . Surface material to be able to adapt to printing and printing ink with good resistance, and have sufficient strength to be able to accept all kinds of processing, such as cutting , waste discharge , slitting , punching and labeling and so on.
In general , any deformable material may be a flexible adhesive material can be used as a fabric , such as commonly used paper , film, composite foil , types of textiles, rubber, thin metal sheet and the like. Types of surfaces depends on the final application and printing processes.
Some materials designed for extreme environmental conditions and design, while others tend to be short -time indoor applications . So now began to use self-adhesive label printing low pollution , waste less green printing materials , printing mostly began to flexo printing and other major green direction.
The following describes some of the labels is produced on the surface material used .
Latexes material : a strong flexible material , it is suitable for curved or cylindrical surfaces. The material of the rubber surface of the paper pulp can be sealed , so that dust and fibers are not spread . This point is particularly important for the tape label , this material was originally designed specifically for this .
Lithoprinting material : There is a very good ink absorption for the scanner. Printed material for its flat surface cleaning and famous , is a high-quality image and barcode printing the best choice.
Anti-clogging material : a shaky rough paper , have a good anti-dirty , suitable for uneven surfaces . This material has a strong and lasting adhesive , commonly used for retail goods price tag.
Casting coating material : is a high gloss pure white printing paper , mainly for advertising and packaging labels. Coating material applied on the computer to be very careful , because the ink may cause stains.
Marking materials : a stiff gray paper , commonly used in the shelf labels , ID labels lapel badges and other needs of stiff material made from this material where the label surface separating from the backing paper to be especially careful, because this material Once crimped ,cable security seals not easily flattened .
Fluorescent materials : also called " white gloss " materials have a variety of bright fluorescent colors. This material is used to emphasize the importance of the document .
Foil laminated or solid material : a layer of thin metal foil is laminated to a paper base formed . The material in dark or bright metal products can often be seen .
Computer printable polyester materials : for heat , moisture , oil , abrasion and most commercial solvents have good resistance . The material is commonly used in the environment requires a lot of durability , such as certain equipment nameplate .
Vinyl : It is a universal durable nonporous plastic , can be used in grease, oil , water and chemical material surface. However vinyl difficult to print because the offset and letterpress ink drying on the surface is very slow . In many cases instead of ethylene with polypropylene .
Satin fabric : synthetic materials belonging , common clothes trademarks, name tag and other needs luxurious appearance package occasions. However, in the preparation of the surface rough silk is difficult to print out high-quality printed products .
Smudgeproof materials : a practical non-coated materials, specifically designed for the rapid absorption of ink . The material is mainly used for electronic data processing (EDP) and other computer printing .
Cited above is the most common types of surface material .container seals No one material to fit any environment, but the diversity of the surface material to meet a variety of different paste environment to ensure proud to meet the needs of most customers .
Then the sticker surface material is a positive acceptance printing graphics , and finally back to accept the adhesive is applied to the material on the pasted object . Surface material to be able to adapt to printing and printing ink with good resistance, and have sufficient strength to be able to accept all kinds of processing, such as cutting , waste discharge , slitting , punching and labeling and so on.
In general , any deformable material may be a flexible adhesive material can be used as a fabric , such as commonly used paper , film, composite foil , types of textiles, rubber, thin metal sheet and the like. Types of surfaces depends on the final application and printing processes.
Some materials designed for extreme environmental conditions and design, while others tend to be short -time indoor applications . So now began to use self-adhesive label printing low pollution , waste less green printing materials , printing mostly began to flexo printing and other major green direction.
The following describes some of the labels is produced on the surface material used .
Latexes material : a strong flexible material , it is suitable for curved or cylindrical surfaces. The material of the rubber surface of the paper pulp can be sealed , so that dust and fibers are not spread . This point is particularly important for the tape label , this material was originally designed specifically for this .
Lithoprinting material : There is a very good ink absorption for the scanner. Printed material for its flat surface cleaning and famous , is a high-quality image and barcode printing the best choice.
Anti-clogging material : a shaky rough paper , have a good anti-dirty , suitable for uneven surfaces . This material has a strong and lasting adhesive , commonly used for retail goods price tag.
Casting coating material : is a high gloss pure white printing paper , mainly for advertising and packaging labels. Coating material applied on the computer to be very careful , because the ink may cause stains.
Marking materials : a stiff gray paper , commonly used in the shelf labels , ID labels lapel badges and other needs of stiff material made from this material where the label surface separating from the backing paper to be especially careful, because this material Once crimped ,cable security seals not easily flattened .
Fluorescent materials : also called " white gloss " materials have a variety of bright fluorescent colors. This material is used to emphasize the importance of the document .
Foil laminated or solid material : a layer of thin metal foil is laminated to a paper base formed . The material in dark or bright metal products can often be seen .
Computer printable polyester materials : for heat , moisture , oil , abrasion and most commercial solvents have good resistance . The material is commonly used in the environment requires a lot of durability , such as certain equipment nameplate .
Vinyl : It is a universal durable nonporous plastic , can be used in grease, oil , water and chemical material surface. However vinyl difficult to print because the offset and letterpress ink drying on the surface is very slow . In many cases instead of ethylene with polypropylene .
Satin fabric : synthetic materials belonging , common clothes trademarks, name tag and other needs luxurious appearance package occasions. However, in the preparation of the surface rough silk is difficult to print out high-quality printed products .
Smudgeproof materials : a practical non-coated materials, specifically designed for the rapid absorption of ink . The material is mainly used for electronic data processing (EDP) and other computer printing .
Cited above is the most common types of surface material .container seals No one material to fit any environment, but the diversity of the surface material to meet a variety of different paste environment to ensure proud to meet the needs of most customers .
Seal packing precautions before installation , how to choose a suitable packing
A seal packing precautions before installing what ?
Sealing Packing Precautions before installation :
Remove old packing stuffing box is pre- installation inspection to prepare the point.
With the old filler filler before the first use special tools to remove all the stuffing box clean
Observe the various parts of the stuffing box without injury eccentricity defects , damage of the stem, bushings and packing stuffing box can affect performance.
Check whether other components can also be applied . Replace all damaged parts .
Second, how to choose a suitable packing ?
How to choose the right packing ? Packing in the selection must take into account two things.
① conditions required performance should be consistent with the packing . According to the relevant technical data to select the most able to meet the requirements of packing.
② sealing requirements must be based on the correct choice packing size. To determine the cross-section ,fixed length plastic strap seal please use the following formula estimates:
Cross-section = ( stuffing box diameter - stem diameter ) / 2
The apparatus of injury may need a larger cross-sectional packing, in order to compensate for damage.
Third, cutting and sealing packing installation pay attention to details
Cutting and sealing packing installation pay attention to details
1 , select the appropriate packing, mechanical precision cut by cutting the required length of the packing ring , without packing cutting machinery, in accordance with packing length L = ( D + packing shaft width S) X1.07X Ji to cutting, generally rotary shaft , a 90 ° straight cut, the valve with a 45 ° cut . Never tried to surround the stuffing box packing to determine the length . Or the packing around the stem with the same . Of a tube, it firmly suppressed, but not stretched packing. Then cut into sample loop , and verify whether it can properly fill the space , and to ensure there are no gaps at its interface . Then be used as a standard sample loop cutting other packing rings . If the finished product on a flat surface finish , soft or easily deformed if the packing can be produced according to a small sample loop tape , and talking under the rope to make the rest of the packing rings .
2, when packing for the valve, tamper evident tapes the valve packing section and the same space , it is best to preload ring: When used in pump, valve packing section and space ( approximately 0.3MM-0.6MM) and the shaft packing has a leak gap in favor lubrication and cooling .
3 , first install a filler ring , make sure no glue each filler dust or other debris . If needed, packing ring on the stem should be the same with the use of clean oil to lubricate . Staggered placement of each packing ring into 90 °. Ring in the axial slowly opened.
Sealing Packing Precautions before installation :
Remove old packing stuffing box is pre- installation inspection to prepare the point.
With the old filler filler before the first use special tools to remove all the stuffing box clean
Observe the various parts of the stuffing box without injury eccentricity defects , damage of the stem, bushings and packing stuffing box can affect performance.
Check whether other components can also be applied . Replace all damaged parts .
Second, how to choose a suitable packing ?
How to choose the right packing ? Packing in the selection must take into account two things.
① conditions required performance should be consistent with the packing . According to the relevant technical data to select the most able to meet the requirements of packing.
② sealing requirements must be based on the correct choice packing size. To determine the cross-section ,fixed length plastic strap seal please use the following formula estimates:
Cross-section = ( stuffing box diameter - stem diameter ) / 2
The apparatus of injury may need a larger cross-sectional packing, in order to compensate for damage.
Third, cutting and sealing packing installation pay attention to details
Cutting and sealing packing installation pay attention to details
1 , select the appropriate packing, mechanical precision cut by cutting the required length of the packing ring , without packing cutting machinery, in accordance with packing length L = ( D + packing shaft width S) X1.07X Ji to cutting, generally rotary shaft , a 90 ° straight cut, the valve with a 45 ° cut . Never tried to surround the stuffing box packing to determine the length . Or the packing around the stem with the same . Of a tube, it firmly suppressed, but not stretched packing. Then cut into sample loop , and verify whether it can properly fill the space , and to ensure there are no gaps at its interface . Then be used as a standard sample loop cutting other packing rings . If the finished product on a flat surface finish , soft or easily deformed if the packing can be produced according to a small sample loop tape , and talking under the rope to make the rest of the packing rings .
2, when packing for the valve, tamper evident tapes the valve packing section and the same space , it is best to preload ring: When used in pump, valve packing section and space ( approximately 0.3MM-0.6MM) and the shaft packing has a leak gap in favor lubrication and cooling .
3 , first install a filler ring , make sure no glue each filler dust or other debris . If needed, packing ring on the stem should be the same with the use of clean oil to lubricate . Staggered placement of each packing ring into 90 °. Ring in the axial slowly opened.
2013年11月3日星期日
Mechanical seal Principle Overview
Mechanical seal is by one pair or several pairs perpendicular to the axis relative to the sliding face in the fluid pressure and compensation institutions elastic ( or magnetic ) to keep under seal affixed to achieve the merger with auxiliary shaft seal leakage resistance device .
Mechanical seal used by the stationary ring ( stationary ring ) 1 , rotating ring ( ring ) 2 , the elastic member 3 , the spring seat 4 , set screws 5 , 6 rotating ring secondary seal , and the stationary ring secondary seal 8 and other components composition, anti-rotation pin 7 is fixed to prevent the gland 9 stationary ring is rotated . Rotating ring and the stationary ring often also according to whether they have the ability to compensate for axial cyclic or compensation is also referred to as compensation .
Mechanical seal possible leakage of fluid channels are A, B, C, D four channels.
C, D leakage channels are stationary ring and the gland , the gland seal between the housing , the two are static seal . B channel between the rotary shaft sealing ring and , when Friction and wear , it can follow the compensation ring only for a small amount of movement in the axial direction , in fact, still a relatively static seal .
Therefore, these leak paths are relatively easy closure. The most commonly used static sealing rubber O-ring or PTFE V-ring , and as compensation or stationary rotating ring ring ring secondary seal , sometimes using both elastic elements feature rubber, PTFE or metal bellows structures.
A channel is a rotating ring and the stationary ring opposite end faces sliding Lamination dynamic seal , it is the mechanical security seals device of the main seal , mechanical seal in determining the performance and life of the key.
Thus , the processing requirements of the seal face is high , while the sealing end faces in order to maintain the necessary lubrication film , the system must be strictly the end surface of the cavity pressure per unit area , the pressure is too large, difficult to form a stable lubricating film , will accelerate the end wear ; pressure is too small , increase of leakage . Therefore, to obtain good sealing performance and enough life , in the design and installation of mechanical seals , we must ensure that the pressure per unit area of face value in the most appropriate range.
Mechanical seal and soft packing seal comparison , has the following advantages: ① sealing is reliable in the long period of operation, the sealed state is very stable, very small leakage , according to rough statistics, the leakage is typically only soft packing seal 1/100 ;stainless steel cable ties ② long life in oil, aqueous medium, generally up to 1 to 2 years or more, usually in the chemical medium can be more than six months ; ③ friction power consumption is small mechanical seal friction power only soft packing seal 10% to 50%.
Mechanical seal used by the stationary ring ( stationary ring ) 1 , rotating ring ( ring ) 2 , the elastic member 3 , the spring seat 4 , set screws 5 , 6 rotating ring secondary seal , and the stationary ring secondary seal 8 and other components composition, anti-rotation pin 7 is fixed to prevent the gland 9 stationary ring is rotated . Rotating ring and the stationary ring often also according to whether they have the ability to compensate for axial cyclic or compensation is also referred to as compensation .
Mechanical seal possible leakage of fluid channels are A, B, C, D four channels.
C, D leakage channels are stationary ring and the gland , the gland seal between the housing , the two are static seal . B channel between the rotary shaft sealing ring and , when Friction and wear , it can follow the compensation ring only for a small amount of movement in the axial direction , in fact, still a relatively static seal .
Therefore, these leak paths are relatively easy closure. The most commonly used static sealing rubber O-ring or PTFE V-ring , and as compensation or stationary rotating ring ring ring secondary seal , sometimes using both elastic elements feature rubber, PTFE or metal bellows structures.
A channel is a rotating ring and the stationary ring opposite end faces sliding Lamination dynamic seal , it is the mechanical security seals device of the main seal , mechanical seal in determining the performance and life of the key.
Thus , the processing requirements of the seal face is high , while the sealing end faces in order to maintain the necessary lubrication film , the system must be strictly the end surface of the cavity pressure per unit area , the pressure is too large, difficult to form a stable lubricating film , will accelerate the end wear ; pressure is too small , increase of leakage . Therefore, to obtain good sealing performance and enough life , in the design and installation of mechanical seals , we must ensure that the pressure per unit area of face value in the most appropriate range.
Mechanical seal and soft packing seal comparison , has the following advantages: ① sealing is reliable in the long period of operation, the sealed state is very stable, very small leakage , according to rough statistics, the leakage is typically only soft packing seal 1/100 ;stainless steel cable ties ② long life in oil, aqueous medium, generally up to 1 to 2 years or more, usually in the chemical medium can be more than six months ; ③ friction power consumption is small mechanical seal friction power only soft packing seal 10% to 50%.
Plant transformation advantages pump seals
Over the operational status of the pump before and after reconstruction comparing this transformation has several advantages .
Save money
Although the transformation of the former investment more ( Note : buy American -made packing guns need 10000.00 yuan / to ; wadding 6000.00 yuan / kg), but because of its durability ,wire seals and is a one-time investment , from a longer time perspective, than with packing can save money by about 30% .
Little maintenance and easy
When the pump runs less time that a leak can be directly injected filler gun to packing room , and do not stop, than the tight packing method to be convenient and effective. And that such filler longer period, generally up to three months ( continuous pump operating conditions ) . Do not need to run for the period just add filler filler.
Sealing effect
Use of effective, safe, using a wide range . As the filler was mashed in a pressure situation tightly, so good sealing effect . The filler mainly composed of carbon fiber , Teflon , Kevlar and other synthetic raw materials , high abrasion resistance , low friction coefficient , and a good impermeability of the protection sleeve is very favorable. By comparison, the life cycle of the sleeve longer than the transformation of the former more than doubled. And it is not only for cold water pump, heat pumps can also be used ( eg drain pump ) , and suitable for different sizes of pumps.
Most power plants in Guang'an stage single-stage overhung centrifugal pump mechanical seal is used ,nylon cable ties it can be in a single-stage double-suction centrifugal pumps ( such as open-cycle cooling water pump ) and other low-pressure pump on the transformation , while reducing maintenance and operating personnel and equipment leaks , and to promote economic efficiency plant .
Save money
Although the transformation of the former investment more ( Note : buy American -made packing guns need 10000.00 yuan / to ; wadding 6000.00 yuan / kg), but because of its durability ,wire seals and is a one-time investment , from a longer time perspective, than with packing can save money by about 30% .
Little maintenance and easy
When the pump runs less time that a leak can be directly injected filler gun to packing room , and do not stop, than the tight packing method to be convenient and effective. And that such filler longer period, generally up to three months ( continuous pump operating conditions ) . Do not need to run for the period just add filler filler.
Sealing effect
Use of effective, safe, using a wide range . As the filler was mashed in a pressure situation tightly, so good sealing effect . The filler mainly composed of carbon fiber , Teflon , Kevlar and other synthetic raw materials , high abrasion resistance , low friction coefficient , and a good impermeability of the protection sleeve is very favorable. By comparison, the life cycle of the sleeve longer than the transformation of the former more than doubled. And it is not only for cold water pump, heat pumps can also be used ( eg drain pump ) , and suitable for different sizes of pumps.
Most power plants in Guang'an stage single-stage overhung centrifugal pump mechanical seal is used ,nylon cable ties it can be in a single-stage double-suction centrifugal pumps ( such as open-cycle cooling water pump ) and other low-pressure pump on the transformation , while reducing maintenance and operating personnel and equipment leaks , and to promote economic efficiency plant .
2013年11月1日星期五
Analysis mixer rotor sealing system
Today, including the production of various components of the rubber compound is mainly used for the mixer . Mix including a polymer , the fine powder filler spread easily , carbon black , calcium carbonate and a small amount of chemicals such as vulcanizing agents , accelerators , or processing aids and a liquid oil component such as plasticized . These liquids and fine powder components are sealed by means of a rotor mixer control system in order to limit their access to the external environment .
Initially , it is easy to distribute these minor ingredients are processed through the film adhesion , called bonding . As the mixing chamber pressure is high , the paste along the rotor shaft is slowly squeezed out. In order to limit the outflow of the paste , both ends of the rotor shaft seal added .
Itself comprises two ring seals , usually in the region having a hard sliding surface . One fixed on the rotor shaft , the relative one rack-mounted . Each rotor sealing system is essentially the difference between the applied surface pressure , divided into automatic rotor seal (SSA), spring - loaded rotor seal (GA) and a hydraulic rotor seal (WYH).
Dustproof design
SSA sealing principle is based on the use of the mixing chamber pressure . If the mixing chamber pressure increases, the pressure will be transmitted to the sliding ring, which seals the locking force will increase . Minimal surface for the application of pressure , the use of disk spring assembly to the internal pressure of the slip ring to the outer fixing ring. Today, a new mixer are equipped with GA and WYH rotor seal system .
In the spring - loaded rotor seal (GA) system , Fixed Length plastic seal located mixing outdoors. Here , the inner ring fixed to the frame , the outer rotating ring fitted to the rotor shaft . Through several ring arranged around the rotary disc spring assembly surface pressure is applied through the pre- pressure of the spring nut . Lubricating plasticizer injection seals the annular gap , will easily spread by some fine bonded rubber components . Deeper lubrication hole in the slide ring fixed to lubricate sliding surfaces.
Rotor seal the water pressure (WYH) case , the sealing position closer to the rotor , in the end of mixing chamber inside the rack . Rotary slip ring fixed to the inner rotor shaft. Through the outer ring with clamping yoke sleeve . The contact pressure is controlled by the hydraulic cylinder and a disc spring assembly produced , the pressure transmitted to the outer sleeve by sliding the yoke ring on the pressure ring . Lubrication and sealing system similar to GA rotor . Since virtually sealing system to the cross-sectional direction of displacement of the mixing chamber , the rotor shaft and wear the gap between the discs , the fine material will occur in this bond .
Comparing these two systems (GA and WYH sealing system ) , it is evident sealing position is clear distinction between the two factors . WYH sealing system as close to the rotor , only a small corner may accumulate materials. On the other hand , the role of movement of wear is easy to fill directly into the sliding surface , and thus adversely affect the wear on the equipment . GA sealing system has a relatively longer annular gap , the annular gap in the powder retention time is long, so that the oil can be better bonded . Therefore , the sliding surface may be protected better , sealing force can be minimized loaded . However , at the same time truck seal, part of the material in the annular gap increases the risk of accumulation , the seal oil is particularly important here .
Initially , it is easy to distribute these minor ingredients are processed through the film adhesion , called bonding . As the mixing chamber pressure is high , the paste along the rotor shaft is slowly squeezed out. In order to limit the outflow of the paste , both ends of the rotor shaft seal added .
Itself comprises two ring seals , usually in the region having a hard sliding surface . One fixed on the rotor shaft , the relative one rack-mounted . Each rotor sealing system is essentially the difference between the applied surface pressure , divided into automatic rotor seal (SSA), spring - loaded rotor seal (GA) and a hydraulic rotor seal (WYH).
Dustproof design
SSA sealing principle is based on the use of the mixing chamber pressure . If the mixing chamber pressure increases, the pressure will be transmitted to the sliding ring, which seals the locking force will increase . Minimal surface for the application of pressure , the use of disk spring assembly to the internal pressure of the slip ring to the outer fixing ring. Today, a new mixer are equipped with GA and WYH rotor seal system .
In the spring - loaded rotor seal (GA) system , Fixed Length plastic seal located mixing outdoors. Here , the inner ring fixed to the frame , the outer rotating ring fitted to the rotor shaft . Through several ring arranged around the rotary disc spring assembly surface pressure is applied through the pre- pressure of the spring nut . Lubricating plasticizer injection seals the annular gap , will easily spread by some fine bonded rubber components . Deeper lubrication hole in the slide ring fixed to lubricate sliding surfaces.
Rotor seal the water pressure (WYH) case , the sealing position closer to the rotor , in the end of mixing chamber inside the rack . Rotary slip ring fixed to the inner rotor shaft. Through the outer ring with clamping yoke sleeve . The contact pressure is controlled by the hydraulic cylinder and a disc spring assembly produced , the pressure transmitted to the outer sleeve by sliding the yoke ring on the pressure ring . Lubrication and sealing system similar to GA rotor . Since virtually sealing system to the cross-sectional direction of displacement of the mixing chamber , the rotor shaft and wear the gap between the discs , the fine material will occur in this bond .
Comparing these two systems (GA and WYH sealing system ) , it is evident sealing position is clear distinction between the two factors . WYH sealing system as close to the rotor , only a small corner may accumulate materials. On the other hand , the role of movement of wear is easy to fill directly into the sliding surface , and thus adversely affect the wear on the equipment . GA sealing system has a relatively longer annular gap , the annular gap in the powder retention time is long, so that the oil can be better bonded . Therefore , the sliding surface may be protected better , sealing force can be minimized loaded . However , at the same time truck seal, part of the material in the annular gap increases the risk of accumulation , the seal oil is particularly important here .
Leakage gasket
The gasket leakage :
General gasket leaks , there are four forms: interface leak , leak penetration , diffusion leaks, damage leak.
Interface Leak : The interface is not as gasket compression flange surface finish combined with improper flange deformation etc will leak in the sealed interface . For interface World leakage , the use of padded material can be clamped against the flange surface .
Penetration leak: Because the soft material of the material are mostly fiber, easy to dip appropriate media , in particular pressure . Due to capillary phenomenon,Fixed Length plastic seals the medium will penetrate into the low pressure side to form infiltration.
Diffusion Leakage: poor concentration , driven by the media or by sealing the gap sealing material produced by mass transfer and capillary leak . Diffusion is the result of molecular motion , and not one-way. Minimal pressure or vacuum in a sealed state , or sealed nitrogen, hydrogen and other permeable substances, as well as highly toxic , radioactive substances should pay special attention penetration and proliferation of two kinds of leaks.
Destruction Leakage: sealing parts relatively poor working conditions , thermal deformation, often affected by vibration, shock , improper installation , fastening force is too large , used repeatedly , deformation , stress concentration, fatigue strength and damage than the material aging , deterioration etc will cause damage leak. pull tight seal This leakage causes the greatest impact hazard is also large , to strengthen prevention.
General gasket leaks , there are four forms: interface leak , leak penetration , diffusion leaks, damage leak.
Interface Leak : The interface is not as gasket compression flange surface finish combined with improper flange deformation etc will leak in the sealed interface . For interface World leakage , the use of padded material can be clamped against the flange surface .
Penetration leak: Because the soft material of the material are mostly fiber, easy to dip appropriate media , in particular pressure . Due to capillary phenomenon,Fixed Length plastic seals the medium will penetrate into the low pressure side to form infiltration.
Diffusion Leakage: poor concentration , driven by the media or by sealing the gap sealing material produced by mass transfer and capillary leak . Diffusion is the result of molecular motion , and not one-way. Minimal pressure or vacuum in a sealed state , or sealed nitrogen, hydrogen and other permeable substances, as well as highly toxic , radioactive substances should pay special attention penetration and proliferation of two kinds of leaks.
Destruction Leakage: sealing parts relatively poor working conditions , thermal deformation, often affected by vibration, shock , improper installation , fastening force is too large , used repeatedly , deformation , stress concentration, fatigue strength and damage than the material aging , deterioration etc will cause damage leak. pull tight seal This leakage causes the greatest impact hazard is also large , to strengthen prevention.
2013年10月31日星期四
Polysulfide sealant polyurethane sealant brief description of the
Sealants are used to fill the gaps ( holes, joints, seams , etc. ) of the material , both bonding and sealing two functions . Polyurethane sealant with silicone sealant,printed cable ties polysulfide sealant sealant composition of the current high-end of the three varieties.
Polyurethane sealant widely used in civil construction, transportation and other industries :
The application of the building - doors and windows , such as glass filled seal ;
In the civil aspects of the application - highways, bridges , runways , etc. caulking seal ;
In automotive applications - window ( mainly windscreen) seal assembly .
Polyurethane sealant has many excellent features ,
Including :
( A ) Performance adjustable range, strong adaptability
( 2 ) good wear resistance ;
( 3 ) mechanical strength ;
( 4 ) good adhesion properties ;
( 5 ) good elasticity , excellent resilience , can be used for dynamic joints ;
( 6 ) good low temperature flexibility ;
( 7 ) good weather resistance, strap seals long service life of 15 to 20 years ;
( 8 ) oil resistance ;
( 9 ) resistance to biological aging ;
( 10 ) affordable.
Polyurethane sealant widely used in civil construction, transportation and other industries :
The application of the building - doors and windows , such as glass filled seal ;
In the civil aspects of the application - highways, bridges , runways , etc. caulking seal ;
In automotive applications - window ( mainly windscreen) seal assembly .
Polyurethane sealant has many excellent features ,
Including :
( A ) Performance adjustable range, strong adaptability
( 2 ) good wear resistance ;
( 3 ) mechanical strength ;
( 4 ) good adhesion properties ;
( 5 ) good elasticity , excellent resilience , can be used for dynamic joints ;
( 6 ) good low temperature flexibility ;
( 7 ) good weather resistance, strap seals long service life of 15 to 20 years ;
( 8 ) oil resistance ;
( 9 ) resistance to biological aging ;
( 10 ) affordable.
High performance soft seal butterfly valve
Characterized in that : said seat ring by a T -shaped tamper evident tape ring on both sides of the soft multi-layer stainless steel sheet .
Valve plate and valve seat sealing surface for the oblique cone structure , oblique cone surface of the valve plate welding temperature, corrosion resistant alloy material ; adjusting ring plate fixed on the spring between the platen adjustment screw assembly structures. This structure effectively compensate for tolerances between the sleeve and the valve stem in the medium band and elastic deformation under pressure to solve the two-way valve in the transmission medium of exchange sealing problems exist in the process .
Use of soft T seals on both sides of multilayer stainless steel sheet , with a metal seal and soft seal the dual advantages of both low and high temperatures, both with zero leakage sealing performance . Test proved positive Chi flow state ( medium flow direction and the disc rotation in the same direction ) , the sealing surface pressure is the transmission of torque and media pressure on the valve plate produced by interaction . Forward medium pressure increases, the valve plate oblique cone surface and the valve seat sealing surface squeezed more tightly , sealing the better .
When the counter state, the valve plate and valve seat seal for containers between the drive torque to the valve plate is pressed against the valve seat . With reverse media pressure , the valve plate and valve seat pressure between the units is less than the medium pressure, adjusting ring spring contained in the subject after the deformation energy stored in compensation valve plate and valve seat sealing surface of the clamping pressure play the role of automatic compensation .
Therefore, the utility model, unlike the existing technologies, as the valve plate mounting hardware multi ring, but directly mounted on the valve body , the middle seat in the platen and an additional adjustment ring is a very good way to two-way seal . It can replace the valve, and ball valve .
Valve plate and valve seat sealing surface for the oblique cone structure , oblique cone surface of the valve plate welding temperature, corrosion resistant alloy material ; adjusting ring plate fixed on the spring between the platen adjustment screw assembly structures. This structure effectively compensate for tolerances between the sleeve and the valve stem in the medium band and elastic deformation under pressure to solve the two-way valve in the transmission medium of exchange sealing problems exist in the process .
Use of soft T seals on both sides of multilayer stainless steel sheet , with a metal seal and soft seal the dual advantages of both low and high temperatures, both with zero leakage sealing performance . Test proved positive Chi flow state ( medium flow direction and the disc rotation in the same direction ) , the sealing surface pressure is the transmission of torque and media pressure on the valve plate produced by interaction . Forward medium pressure increases, the valve plate oblique cone surface and the valve seat sealing surface squeezed more tightly , sealing the better .
When the counter state, the valve plate and valve seat seal for containers between the drive torque to the valve plate is pressed against the valve seat . With reverse media pressure , the valve plate and valve seat pressure between the units is less than the medium pressure, adjusting ring spring contained in the subject after the deformation energy stored in compensation valve plate and valve seat sealing surface of the clamping pressure play the role of automatic compensation .
Therefore, the utility model, unlike the existing technologies, as the valve plate mounting hardware multi ring, but directly mounted on the valve body , the middle seat in the platen and an additional adjustment ring is a very good way to two-way seal . It can replace the valve, and ball valve .
2013年10月28日星期一
Porous mechanical seal processing methods Analysis
Mechanical seal mechanical security seals structure of porous structure. Ring seal ring is flat, flat end face of the stationary ring arranged with uniform pores rules to form a porous face. Microporous round hole, oval hole or tapered bore.
Diameter from a few microns to hundreds of microns, hole depth from a few microns to tens of microns, porosity (pore area percentage of the total face area) from 5% to 30%.indicative seals The surface roughness of the porous end with the same stationary ring surface roughness, Ra are 0.01 ~ 0.02μm.
Porous mechanical seal processing methods
Cover depth micron processing flow slots or pores, conventional machining methods are almost powerless. So people explored a variety of processing methods, mainly the following: photochemical etching process (photolithography), EDM (electric etching), electrochemical machining and laser processing method.
Compared to conventional processing techniques, laser processing for a wide range of different materials, different shapes are suitable for machined surfaces with no mechanical deformation of the workpiece, clean, fast, good repeatability and high degree of automation. Obviously, for the porous mechanical seal rings, the other processing methods are powerless, only the use of the laser processing method in order to obtain satisfactory results.
Friction performance test
End load with the seal ring, respectively, and the common seal ring laser processing porous comparison test, two kinds of seal ring face size, surface roughness, end load and speed, etc. are identical test conditions, carbon graphite material of the seal ring sealing ring paired with both tests run. Laser Surface mechanical seal mechanical seal friction coefficient than the average coefficient of friction is much lower. From the friction coefficient of view, high security bolt sealsordinary mechanical seal friction coefficient in boundary friction state, and laser processing porous mechanical seal friction coefficient in mixed and even liquid friction state, therefore, the laser processing of porous seal ring seal rings than ordinary has better friction properties.
Diameter from a few microns to hundreds of microns, hole depth from a few microns to tens of microns, porosity (pore area percentage of the total face area) from 5% to 30%.indicative seals The surface roughness of the porous end with the same stationary ring surface roughness, Ra are 0.01 ~ 0.02μm.
Porous mechanical seal processing methods
Cover depth micron processing flow slots or pores, conventional machining methods are almost powerless. So people explored a variety of processing methods, mainly the following: photochemical etching process (photolithography), EDM (electric etching), electrochemical machining and laser processing method.
Compared to conventional processing techniques, laser processing for a wide range of different materials, different shapes are suitable for machined surfaces with no mechanical deformation of the workpiece, clean, fast, good repeatability and high degree of automation. Obviously, for the porous mechanical seal rings, the other processing methods are powerless, only the use of the laser processing method in order to obtain satisfactory results.
Friction performance test
End load with the seal ring, respectively, and the common seal ring laser processing porous comparison test, two kinds of seal ring face size, surface roughness, end load and speed, etc. are identical test conditions, carbon graphite material of the seal ring sealing ring paired with both tests run. Laser Surface mechanical seal mechanical seal friction coefficient than the average coefficient of friction is much lower. From the friction coefficient of view, high security bolt sealsordinary mechanical seal friction coefficient in boundary friction state, and laser processing porous mechanical seal friction coefficient in mixed and even liquid friction state, therefore, the laser processing of porous seal ring seal rings than ordinary has better friction properties.
About the gear pump mechanical seal requirements
Mechanical seals, also known as face seal (Mechanicalseal), is a dynamic seal rotating shaft mechanical seal performance and reliable amount of leakage, long life, low power consumption. Need frequent maintenance, and can adapt to the production process automation and high temperature, low temperature, pressure, vacuum, high speed, and various corrosive media. medium containing solid particles and other harsh conditions of the hungry sealing requirements. mechanical seal is rely on one or more pairs of lip perpendicular to the axis relative to the end face of the fluid dynamic pressure and the compensation mechanism stretch * (or magnetic) to keep under seal and then combined with the auxiliary shaft seal leakage resistance achieved devices gear pump mechanical seal requirements, mechanical tamper seals and soft packing seal is as follows:
Benefits:
1) reliable sealing, long-term operation in a sealed state is very stable, very small leak, the leak is about 1% of soft packing seal:
2) long life, in oil, water media generally up to 1 to 2 years or longer in the chemical medium generally work more than six months:
3) rub the power consumption, the friction power is only the soft packing seal 10% to 50%
4) essentially no shaft or sleeve wear:
5) maintenance cycle. Face wear can be automatically compensated, under normal circumstances do not require regular maintenance and repair:
6) resistance to shock, vibration of the rotating shaft and the shaft deflection of the sealed chamber insensitive:
7) applies to a wide range of mechanical numbered seals can be used for high temperature, low temperature, high pressure, vacuum, different rotation frequency, and a variety of corrosive media and media containing abrasive seal.
Benefits:
1) reliable sealing, long-term operation in a sealed state is very stable, very small leak, the leak is about 1% of soft packing seal:
2) long life, in oil, water media generally up to 1 to 2 years or longer in the chemical medium generally work more than six months:
3) rub the power consumption, the friction power is only the soft packing seal 10% to 50%
4) essentially no shaft or sleeve wear:
5) maintenance cycle. Face wear can be automatically compensated, under normal circumstances do not require regular maintenance and repair:
6) resistance to shock, vibration of the rotating shaft and the shaft deflection of the sealed chamber insensitive:
7) applies to a wide range of mechanical numbered seals can be used for high temperature, low temperature, high pressure, vacuum, different rotation frequency, and a variety of corrosive media and media containing abrasive seal.
2013年10月27日星期日
Three eccentric metal seal butterfly valve structural features interpreted
1 , three eccentric multi-level metal seal butterfly valve butterfly plate stacked rings of hard and soft metal sheets , metal seals and elastomeric seals with the dual advantages of both low and high temperatures, both with excellent sealing performance.
2 , the use of three-dimensional eccentric structure , seat and disc almost no friction parts inside the valve when closed almost no damage ; This structure greatly improves the performance of the valve in use . And has a more closed more tightly sealing function .
3 , the stem , the lower part is equipped with bushings , each bushing wear and friction generated is small , this structure can prevent wear and adhesion, but also improve the service life.
4, the valve sealing surface , the use of alloy steel or stellite alloy,barrier security seals sealing surface abrasion, erosion , corrosion resistance ; long service life.
5 , unique structure , switching torque is small , flexible operation, labor-saving , convenient, high pressure from the media , low-impact , reliable sealing performance . Can be used for opening and closing and regulating equipment .
2 , the use of three-dimensional eccentric structure , seat and disc almost no friction parts inside the valve when closed almost no damage ; This structure greatly improves the performance of the valve in use . And has a more closed more tightly sealing function .
3 , the stem , the lower part is equipped with bushings , each bushing wear and friction generated is small , this structure can prevent wear and adhesion, but also improve the service life.
4, the valve sealing surface , the use of alloy steel or stellite alloy,barrier security seals sealing surface abrasion, erosion , corrosion resistance ; long service life.
5 , unique structure , switching torque is small , flexible operation, labor-saving , convenient, high pressure from the media , low-impact , reliable sealing performance . Can be used for opening and closing and regulating equipment .
Soft sealing gate by friction resolve technical design
First, the technical background :
Existing in the body of the valve , the valve cover and the case member are intact , only slight deformation or corrosion of the sealing surface , the valve can not be used . Fix these valves non-professional plant can not, therefore resulting in a great waste . Therefore, the use of units of hope Valve is : seat , the valve plate sealing surface is not easy deformation , corrosion , wearing sealing material can be changed . In opening and closing the valve plate not to have friction with the sealing surface or minimize friction, avoid soft sealing gate various deficiencies .
Second, the purpose of the invention :
Solve the seat and the valve plate sealing surface corrosion or deformation , the valve plate can automatically compensate and close the cover and press the soft sealing gate automatic pressure balance between the problems solved by the soft sealing material sealing surface friction and damage problems due to the valve sealing cap can be changed, greatly increased the use of valves .
Third, the practical range :
Bore φ50-φ400mm, pressure 2.5-4.0MPa, less than 200 ℃ for various liquid at room temperature
Fourth, the technical solutions :
The valves are double parallel gate valve , numbered seals inlet seals, inlet valve plate by a sealing sleeve and unloading force composed mainly sealed gate valve plate . Sealing sleeve and valve plate unloading force synchronous movement but not connected to the pipeline pressure through the valve plate unloading force , leveling arm passed to the exit side of the seat , which will greatly improve the soft sealing surface adhesion. Valve plate outside the set of a corrosion-resistant rubber seal sets. Soft sealing material in the opening and closing process , and the seat to keep a certain distance , the soft sealing material in the absence of friction without folding pressure environment. Gland in the pipeline transportation of the liquid components within the valve isolation , nylon cable tie corrosion and impurities from the liquid blocking . This valve is very easy to replace a sealing material , so the service life is generally more than 5 times the gate valve .
Existing in the body of the valve , the valve cover and the case member are intact , only slight deformation or corrosion of the sealing surface , the valve can not be used . Fix these valves non-professional plant can not, therefore resulting in a great waste . Therefore, the use of units of hope Valve is : seat , the valve plate sealing surface is not easy deformation , corrosion , wearing sealing material can be changed . In opening and closing the valve plate not to have friction with the sealing surface or minimize friction, avoid soft sealing gate various deficiencies .
Second, the purpose of the invention :
Solve the seat and the valve plate sealing surface corrosion or deformation , the valve plate can automatically compensate and close the cover and press the soft sealing gate automatic pressure balance between the problems solved by the soft sealing material sealing surface friction and damage problems due to the valve sealing cap can be changed, greatly increased the use of valves .
Third, the practical range :
Bore φ50-φ400mm, pressure 2.5-4.0MPa, less than 200 ℃ for various liquid at room temperature
Fourth, the technical solutions :
The valves are double parallel gate valve , numbered seals inlet seals, inlet valve plate by a sealing sleeve and unloading force composed mainly sealed gate valve plate . Sealing sleeve and valve plate unloading force synchronous movement but not connected to the pipeline pressure through the valve plate unloading force , leveling arm passed to the exit side of the seat , which will greatly improve the soft sealing surface adhesion. Valve plate outside the set of a corrosion-resistant rubber seal sets. Soft sealing material in the opening and closing process , and the seat to keep a certain distance , the soft sealing material in the absence of friction without folding pressure environment. Gland in the pipeline transportation of the liquid components within the valve isolation , nylon cable tie corrosion and impurities from the liquid blocking . This valve is very easy to replace a sealing material , so the service life is generally more than 5 times the gate valve .
2013年10月26日星期六
Machine impurities into the seal face wear and tear caused by
The seal face contact and friction is normal, can enter the seal face of the solid impurities are very subtle , it is easy to seal water away , so there is no leakage of the sealing effect . Larger solid particles into the seal face , causing increased wear of the case , are not working properly sealed occur . Divided into the following situations:
( 1 ) In the downtime or maintenance after the initial test , the pipe seal dirty or poor water quality , solid impurities easy access to the seal faces . Therefore, the mechanical seal friction surface wear faster .
( 2 ) double mechanical seal in the sealing water pressure fluctuations , or below the pump , the pressure inside the pump body with chemical impurities into the medium from the inner end face of the seal chamber , some impurities remain in the sealed end face , resulting in increased wear and tear , single-acting mechanical seal built , due to media pressure fluctuations , seal face into the possibility of impurities is much smaller than the double-end , relatively longer life expectancy.
( 3 ) due to various reasons impurities into the seal face . Early peroxide mechanical seal face severe wear , wear mechanism from view, the main particle abrasion , adhesion wear only take place in a particular case , so we only discuss the wear particles . Peroxide particles wear rate is high , greatly reducing the service life of mechanical seals . Wear particles not only soft sealing ring ( graphite ring ) wear , but also hard seal ring ( mainly carbide ring ) wear particles generally worn surface has obvious rules nicks and grooves. The essence of wear particles in the vertical component of the hard particles under the action of the friction surface piercing , while under the action of the tangential component of the relative movement, so that the friction surface micro- machining process and plow . Wear particles and the hardness of the material not only than the pressure on the end face , and the microstructure of the material and the test temperature , load and stress the nature of the size , the size and hardness of the abrasive and chemical properties of the friction surface and other factors.
Friction pairing material hardness difference , tamper seal tape a great impact on the wear particles . Friction large difference in hardness , wear particles appear much less the case , friction and wear rate is also small ; but the hardness difference is small , the more wear particles occurs . The main reason is because when particles invade friction , high hardness in the ring , only embedded in graphite or graphite ring on the ring groove on wiping the hard ring is not bruised, but also to maintain the original finish , over a period of time the particles may also be sealed water washed away. The particles invade the friction surface , moving ring hardness is low, due to the hard ring is scratched , the effect of vibration and eccentric , such as rasp file graphite ring , causing serious wear and tear. Meanwhile abrasions ring itself is also growing . After running-in , snap ring groove surface and the surface of the graphite ring concentric grooves gradually coincide , then the leakage reduction .
In addition , stationary ring or ring leakage inlet end , if the chamfering is too large, larger particles can also lead into the friction surface along the slope , causing premature wear .
For special circumstances , tamper evident label special measures should be adopted , in the car or the initial sealing water is quite poor , in order to avoid premature wear of the mechanical seal failure , end than the pressure to increase the use of temporary practice , you can receive significant effect , due to increase spring pressure and no significant increase in friction wear particles contrary avoid early wear and extended service life.
( 1 ) In the downtime or maintenance after the initial test , the pipe seal dirty or poor water quality , solid impurities easy access to the seal faces . Therefore, the mechanical seal friction surface wear faster .
( 2 ) double mechanical seal in the sealing water pressure fluctuations , or below the pump , the pressure inside the pump body with chemical impurities into the medium from the inner end face of the seal chamber , some impurities remain in the sealed end face , resulting in increased wear and tear , single-acting mechanical seal built , due to media pressure fluctuations , seal face into the possibility of impurities is much smaller than the double-end , relatively longer life expectancy.
( 3 ) due to various reasons impurities into the seal face . Early peroxide mechanical seal face severe wear , wear mechanism from view, the main particle abrasion , adhesion wear only take place in a particular case , so we only discuss the wear particles . Peroxide particles wear rate is high , greatly reducing the service life of mechanical seals . Wear particles not only soft sealing ring ( graphite ring ) wear , but also hard seal ring ( mainly carbide ring ) wear particles generally worn surface has obvious rules nicks and grooves. The essence of wear particles in the vertical component of the hard particles under the action of the friction surface piercing , while under the action of the tangential component of the relative movement, so that the friction surface micro- machining process and plow . Wear particles and the hardness of the material not only than the pressure on the end face , and the microstructure of the material and the test temperature , load and stress the nature of the size , the size and hardness of the abrasive and chemical properties of the friction surface and other factors.
Friction pairing material hardness difference , tamper seal tape a great impact on the wear particles . Friction large difference in hardness , wear particles appear much less the case , friction and wear rate is also small ; but the hardness difference is small , the more wear particles occurs . The main reason is because when particles invade friction , high hardness in the ring , only embedded in graphite or graphite ring on the ring groove on wiping the hard ring is not bruised, but also to maintain the original finish , over a period of time the particles may also be sealed water washed away. The particles invade the friction surface , moving ring hardness is low, due to the hard ring is scratched , the effect of vibration and eccentric , such as rasp file graphite ring , causing serious wear and tear. Meanwhile abrasions ring itself is also growing . After running-in , snap ring groove surface and the surface of the graphite ring concentric grooves gradually coincide , then the leakage reduction .
In addition , stationary ring or ring leakage inlet end , if the chamfering is too large, larger particles can also lead into the friction surface along the slope , causing premature wear .
For special circumstances , tamper evident label special measures should be adopted , in the car or the initial sealing water is quite poor , in order to avoid premature wear of the mechanical seal failure , end than the pressure to increase the use of temporary practice , you can receive significant effect , due to increase spring pressure and no significant increase in friction wear particles contrary avoid early wear and extended service life.
Centrifugal pump mechanical seal failure causes
1, the static ring sealing surface leakage
Main reasons are: face flatness, roughness does not meet the requirements, or surface scratches ; face between particulate matter , resulting in both ends of the surface can not be the same run ; installed in place , incorrectly.
2 , the compensation ring seal leak
Main reasons are: gland deformation, uneven preload ; installed incorrectly ; seals do not meet quality standards ; ring selection is wrong.
Actual results showed that most parts of the failure of the sealing element is dynamic and static ring end face mechanical seal centrifugal dynamic and static ring face is a common failure occurs cracking phenomenon for two main reasons :
① sealing surface when installing the gap is too big , too late to rinse away the heat generated by friction ; flushing fluid leakage from the sealing surface clearance to go , resulting in overheating and damage to the end face .
② liquid medium vapor expansion , so that both ends of the surface by the vapor expansion force to separate , when the two sealing surfaces when bonding force , resulting in destruction of the lubricating film facing surface overheating.
③ poor lubricating liquid medium , together with the operating pressure overload, the two sealing surfaces trace rotation is not synchronized. Such as high speed pump speed is 20445r/min, central diameter of the sealing surface 7cm, pump operation after the line speed up 75m / s, when there is a lag can not track the rotating sealing surface , the sealing surface is damaged resulting in instantaneous temperature .
④ sealing fluid orifice or filter is clogged , causing water shortage, so that the mechanical seal failure.
In addition , the sealing surface slippery surface ditch , face a gap of bonding lead to failure of the sealing element ,nylon cable ties two main reasons:
① dirty liquid medium , a small hard particles , people at high speed sliding sealing surface , the end surface scratches and failure.
② poor coaxial transmission parts pump , the pump is turned face each revolution is shaking friction once, moving ring running track misalignment , causing vaporization face , overheating wear.
③ liquid medium caused by the frequent occurrence of hydraulic characteristics of pump vibration , resulting in the sealing surface dislocation and failure.
The sealing element is a liquid medium corrosion, stress concentration , with soft and hard materials , erosion , secondary seal O-ring , V -ring , is not compatible with the liquid medium concave ring , deformation, surface damage can cause failure of the mechanical metal cable ties , so form of damage to its comprehensive analysis to identify the root cause , to ensure the long-running mechanical seals .
Main reasons are: face flatness, roughness does not meet the requirements, or surface scratches ; face between particulate matter , resulting in both ends of the surface can not be the same run ; installed in place , incorrectly.
2 , the compensation ring seal leak
Main reasons are: gland deformation, uneven preload ; installed incorrectly ; seals do not meet quality standards ; ring selection is wrong.
Actual results showed that most parts of the failure of the sealing element is dynamic and static ring end face mechanical seal centrifugal dynamic and static ring face is a common failure occurs cracking phenomenon for two main reasons :
① sealing surface when installing the gap is too big , too late to rinse away the heat generated by friction ; flushing fluid leakage from the sealing surface clearance to go , resulting in overheating and damage to the end face .
② liquid medium vapor expansion , so that both ends of the surface by the vapor expansion force to separate , when the two sealing surfaces when bonding force , resulting in destruction of the lubricating film facing surface overheating.
③ poor lubricating liquid medium , together with the operating pressure overload, the two sealing surfaces trace rotation is not synchronized. Such as high speed pump speed is 20445r/min, central diameter of the sealing surface 7cm, pump operation after the line speed up 75m / s, when there is a lag can not track the rotating sealing surface , the sealing surface is damaged resulting in instantaneous temperature .
④ sealing fluid orifice or filter is clogged , causing water shortage, so that the mechanical seal failure.
In addition , the sealing surface slippery surface ditch , face a gap of bonding lead to failure of the sealing element ,nylon cable ties two main reasons:
① dirty liquid medium , a small hard particles , people at high speed sliding sealing surface , the end surface scratches and failure.
② poor coaxial transmission parts pump , the pump is turned face each revolution is shaking friction once, moving ring running track misalignment , causing vaporization face , overheating wear.
③ liquid medium caused by the frequent occurrence of hydraulic characteristics of pump vibration , resulting in the sealing surface dislocation and failure.
The sealing element is a liquid medium corrosion, stress concentration , with soft and hard materials , erosion , secondary seal O-ring , V -ring , is not compatible with the liquid medium concave ring , deformation, surface damage can cause failure of the mechanical metal cable ties , so form of damage to its comprehensive analysis to identify the root cause , to ensure the long-running mechanical seals .
2013年10月24日星期四
Polysulfide sealant range of applications
Although polysulfide sealant expensive, application subject to certain restrictions, but because it has a variety of excellent physical and chemical properties, so in a variety of major projects on both widely used.
1 , the construction industry : a large building roof seal. Such as the Three Gorges Left Bank Power House roof,container security seals the roof of Chairman Mao Memorial Hall , Tiananmen roof.
2 , hydraulic : Shanxi Yellow River Diversion Project , the Three Gorges permanent lock of expansion joints, Guangdong Dongjiang-Shenzhen Water Diversion Project .
3 , the airport road : western suburbs of Beijing airport renovations , Zhengzhou airport , airport Zhangjiakou part of the project .
4 , sewage treatment plants : According to incomplete statistics, 80% of domestic sewage treatment plant expansion joints are sealed using polysulfide sealant .
5 , Metro and Tunnel : Beijing subway station Andingmen waterproofing , Tiananmen East Station roof are sealed with a polysulfide sealant .
6 , aerospace industry: aircraft fuel tanks, cockpit seals ( military products ) .
7 , the automotive industry : car door shock seal.
8 , petrochemicals : gasoline, kerosene , diesel fuel storage tanks of various anti-corrosion seal. meter seals Chemical product storage tank seal , such as Power Group PAC workshop Jiaozuo Chemical storage tank is the crystallization of our sealant, a long time in about 80 ℃ and acidic environments, has been more than six months found no leaks phenomenon .
9, the electrical and electronic industry: such as refrigerators, freezers glass doors.
1 , the construction industry : a large building roof seal. Such as the Three Gorges Left Bank Power House roof,container security seals the roof of Chairman Mao Memorial Hall , Tiananmen roof.
2 , hydraulic : Shanxi Yellow River Diversion Project , the Three Gorges permanent lock of expansion joints, Guangdong Dongjiang-Shenzhen Water Diversion Project .
3 , the airport road : western suburbs of Beijing airport renovations , Zhengzhou airport , airport Zhangjiakou part of the project .
4 , sewage treatment plants : According to incomplete statistics, 80% of domestic sewage treatment plant expansion joints are sealed using polysulfide sealant .
5 , Metro and Tunnel : Beijing subway station Andingmen waterproofing , Tiananmen East Station roof are sealed with a polysulfide sealant .
6 , aerospace industry: aircraft fuel tanks, cockpit seals ( military products ) .
7 , the automotive industry : car door shock seal.
8 , petrochemicals : gasoline, kerosene , diesel fuel storage tanks of various anti-corrosion seal. meter seals Chemical product storage tank seal , such as Power Group PAC workshop Jiaozuo Chemical storage tank is the crystallization of our sealant, a long time in about 80 ℃ and acidic environments, has been more than six months found no leaks phenomenon .
9, the electrical and electronic industry: such as refrigerators, freezers glass doors.
Slag pump mechanical seal
Slag pump is a gear pump , the mechanical seal device and discuss problems , also called seal mechanical seal , he is relying on springs and seals in the pressure of the media twisted the ring and stationary outer ring contact pressing force occurred on the right , is that the two end faces tight fit. Face a very thin oil film between the stick ,high security seal when the media after great resistance to prevent liquid leak , in order to reach the goal sealed , while the ring and stationary ring has a smooth probation . Adapt well to complete no leak .
Mechanical seal features: slag disposal pump mechanical seal problems and discussion of the mechanical seal primary strengths are sealed securely in an application cycle, leaked rarely ; probation long life, you can usually use five years ; maintenance cycle. But the mechanical seal structure is complicated, built-in , repairing mechanical seal pump should stop crashes often heavy workload . Thus , to ensure reliable mechanical seal work , delay the use and life of the mechanical seal is very important.
Mechanical seals in their daily operations , prone to many problems. Mechanical seals to attack the primary problem is the amount of leaked tolerance and temperature is too high, touch the mechanical seal gland, If you can not stay on top , to clarify the temperature is too high. Leaked amount should not exceed 60 drops each side / min.wire seals If a linear flow , then clarified excessive leak can be sure they can look operation ; if outward injection , you should immediately check the downtime
Mechanical seal features: slag disposal pump mechanical seal problems and discussion of the mechanical seal primary strengths are sealed securely in an application cycle, leaked rarely ; probation long life, you can usually use five years ; maintenance cycle. But the mechanical seal structure is complicated, built-in , repairing mechanical seal pump should stop crashes often heavy workload . Thus , to ensure reliable mechanical seal work , delay the use and life of the mechanical seal is very important.
Mechanical seals in their daily operations , prone to many problems. Mechanical seals to attack the primary problem is the amount of leaked tolerance and temperature is too high, touch the mechanical seal gland, If you can not stay on top , to clarify the temperature is too high. Leaked amount should not exceed 60 drops each side / min.wire seals If a linear flow , then clarified excessive leak can be sure they can look operation ; if outward injection , you should immediately check the downtime
2013年10月23日星期三
Factors affecting the performance of the valve seal
Assessment of the valve is the valve sealing performance merits of the main indicators of quality . Valve sealing performance mainly include two aspects, namely, leakage and leakage . Endoleak refers to the closure member between the valve seat and sealing of the media reach , assessment criteria within the country there are two missing . One is the State Technical Supervision Bureau released in December 1992 , June 1, 1993 began the implementation of a national standard GB/T13927-1992 " universal valve pressure test ." This standard is used with reference to the international standard ISO5208-1982 " industrial valves valve pressure test " developed ; another was issued by the Ministry of Machinery Industry JB/T9092-1999 " valve testing and inspection ," This standard is referenced API598- 1986 " valve inspection and test " developed . GB/T13927-1992 for general industrial valves inspection ; JB/T9092-1999 industrial valves for the oil inspection . Leakage refers to the parts of the stem packing leak , the leak in the flange gasket and valve parts casting defects caused due to leakage, leakage is simply not allowed. If the media is not allowed into the atmosphere , then the leakage of seal leakage than the inner seal more important. Therefore, the valve sealing performance should lead to the manufacturer 's attention.
Factors affecting the performance of the main valve seal are: ① sealing surface quality ; ② sealing surface width ;plastic padlock security seals ③ valve before and after the valve pressure difference ; ④ sealing surface material and its processing status ; ⑤ media properties ; ⑥ surface hydrophilicity ; ⑦ seal film presence ; ⑧ closed parts of rigidity and structural characteristics .
⑴ quality sealing surface of the valve sealing performance of the sealing surface of the valve seat and the closure member is in contact with each other to shut down part. When the sealing surface pressure at 40MPa or less, the quality of the sealing surface of the valve sealing performance play a decisive role . This is because : When the sealing surface pressure is small, low surface roughness , the leakage is increasing rapidly . When the sealing surface pressure is large, the surface roughness on the leakage has been significantly reduced .
⑵ width on the valve sealing surface of the sealing performance of the sealing surface width determines the length of the pores . When the width is increased, fluid movement along the pores stroke lengthened to increase the resistance movement . Can be reduced to increase the width of the sealing surface pressure in the valve erosive wear . Increase the width of the sealing surface , it will cause leakage increased in proportion to the stroke length , and thus be able to proportionately reduce leakage. But the sealing surface width increases , in the same sealing force , vehicle seals the sealing pressure than decreases, but also make the possibility of leakage increases. Therefore, the increase can not be unlimited sealing surface width.
⑶ valve before and after the valve differential pressure on the valve sealing performance is analyzed theoretically , valves before and after the valve pressure difference is proportional to both the amount of leakage . But tests proved : in other conditions are the same , the leakage volume growth is increasing pressure differential over . Leakage between the pressure difference can be approximated by the following formula : G = M (N △ P2 + S △ P) where : M, N, S - constant coefficients, which depend on the material , the sealing surface processing quality , the sealing surface pressure and other conditions ; △ P - pressure differential.
⑷ sealing surface materials and their processing status on the valve sealing performance of the sealing surface materials and their processing status of the valve leakage have a great impact . As the remaining gap between the seal faces depends on the sealing surface micro-roughness , so that , if the use of steel materials, seals, resulting in sealing of the same , there must be greater than the pressure , the value must exceed brass system value than the pressure seal . The sealing surface of the processing state , such as a peak distortion , and sealing the gap size changes and other phenomena occur on the metal surface , it is clear that the performance of the surface properties of the base material have significant difference . Induced changes in the machining surface can affect the thickness of 50μm. Grinding the base metal is not exposed . Work is different from the metal surface tissue matrix organization . Geometry and material properties and microstructure geometry compared to little effect . Differences in the performance of metal , usually less than other factors . Sealing surface when working under low pressure conditions , the situation is more prominent. When the pressure ratio is higher than 40MPa , the surface roughness of the sealing performance is reduced , and the impact of the material is increased.
Factors affecting the performance of the main valve seal are: ① sealing surface quality ; ② sealing surface width ;plastic padlock security seals ③ valve before and after the valve pressure difference ; ④ sealing surface material and its processing status ; ⑤ media properties ; ⑥ surface hydrophilicity ; ⑦ seal film presence ; ⑧ closed parts of rigidity and structural characteristics .
⑴ quality sealing surface of the valve sealing performance of the sealing surface of the valve seat and the closure member is in contact with each other to shut down part. When the sealing surface pressure at 40MPa or less, the quality of the sealing surface of the valve sealing performance play a decisive role . This is because : When the sealing surface pressure is small, low surface roughness , the leakage is increasing rapidly . When the sealing surface pressure is large, the surface roughness on the leakage has been significantly reduced .
⑵ width on the valve sealing surface of the sealing performance of the sealing surface width determines the length of the pores . When the width is increased, fluid movement along the pores stroke lengthened to increase the resistance movement . Can be reduced to increase the width of the sealing surface pressure in the valve erosive wear . Increase the width of the sealing surface , it will cause leakage increased in proportion to the stroke length , and thus be able to proportionately reduce leakage. But the sealing surface width increases , in the same sealing force , vehicle seals the sealing pressure than decreases, but also make the possibility of leakage increases. Therefore, the increase can not be unlimited sealing surface width.
⑶ valve before and after the valve differential pressure on the valve sealing performance is analyzed theoretically , valves before and after the valve pressure difference is proportional to both the amount of leakage . But tests proved : in other conditions are the same , the leakage volume growth is increasing pressure differential over . Leakage between the pressure difference can be approximated by the following formula : G = M (N △ P2 + S △ P) where : M, N, S - constant coefficients, which depend on the material , the sealing surface processing quality , the sealing surface pressure and other conditions ; △ P - pressure differential.
⑷ sealing surface materials and their processing status on the valve sealing performance of the sealing surface materials and their processing status of the valve leakage have a great impact . As the remaining gap between the seal faces depends on the sealing surface micro-roughness , so that , if the use of steel materials, seals, resulting in sealing of the same , there must be greater than the pressure , the value must exceed brass system value than the pressure seal . The sealing surface of the processing state , such as a peak distortion , and sealing the gap size changes and other phenomena occur on the metal surface , it is clear that the performance of the surface properties of the base material have significant difference . Induced changes in the machining surface can affect the thickness of 50μm. Grinding the base metal is not exposed . Work is different from the metal surface tissue matrix organization . Geometry and material properties and microstructure geometry compared to little effect . Differences in the performance of metal , usually less than other factors . Sealing surface when working under low pressure conditions , the situation is more prominent. When the pressure ratio is higher than 40MPa , the surface roughness of the sealing performance is reduced , and the impact of the material is increased.
Spiral Labyrinth Seal
Spiral labyrinth seal is used in industry long ago, and it is different from the spiral seal in that: the axis of the helical groove machined surface , the holes in the sealing collar is made also vehicles , and has opposite the shaft screwed to the shaft and screw suites stark turbulent flow . Additionally , labyrinth seal spiral screw velocity higher than the sealing screw , which turbulent flow conditions for low viscosity liquids. cable marker ties Spiral laminar flow conditions generally used for sealing large -viscosity liquid ( such as viscosity liquids than water ) .
How it works: In between the screw and the threaded sleeve work space, the liquid in the collar two tooth surfaces and screw two tooth surfaces bounded by a number of cellular space . Screw and the gap between the threaded sleeve surface was grooved annular cylinder . Fluid through the vortex formed when the threads , the direction of flow in the opposite direction . As the screw fluid flow around a momentum exchange results , security seals screw the energy to liquid. Helix and threaded sleeve with the liquid interaction that results in through the gap between the screw and the threaded sleeve surface frictional force is generated in the name of boundaries . Friction generated by the liquid in between the screw and the threaded sleeve pressure .
How it works: In between the screw and the threaded sleeve work space, the liquid in the collar two tooth surfaces and screw two tooth surfaces bounded by a number of cellular space . Screw and the gap between the threaded sleeve surface was grooved annular cylinder . Fluid through the vortex formed when the threads , the direction of flow in the opposite direction . As the screw fluid flow around a momentum exchange results , security seals screw the energy to liquid. Helix and threaded sleeve with the liquid interaction that results in through the gap between the screw and the threaded sleeve surface frictional force is generated in the name of boundaries . Friction generated by the liquid in between the screw and the threaded sleeve pressure .
2013年10月22日星期二
Several sealing material on Q
1 fluorine rubber and nitrile materials What is the difference ?
Answer : Viton and NBR rubber seals are commonly used materials . As for petroleum based hydraulic fluids nitrile better compatibility , as a sealing material has good stability ,metal security seals the price is cheap, so in the hydraulic , pneumatic seal widely used. Viton is the best overall performance synthetic rubber sealing rubber . Carbon atoms, fluorine rubber, a fluorine atom primary key replacement, stable molecular structure . Its heat resistance, good chemical stability. Therefore, in high temperature applications and special occasions more media .
(2) What is the rubber material elongation ?
A: The elongation rate is the reciprocal of stiffness of a material index , the amount of materials used in the natural state of tension length ratio expressed as a percentage . Material allows elongation is not in permanent damage or permanent deformation occurs before the maximum elongation.
3 What rubber material breathable ?
A: refers to the gas permeability of the material in pneumatic sealing and vacuum -sealed material should be noted that this performance .
4 sealing material FPM, FKM What is the difference ?
Answer : FPM is ISO 1629 abbreviation of fluorine rubber , FKM Viton is ASTM 1418 in the name abbreviation . FPM and FKM are referring to the same kind of Viton, wording is different because the European and American English are spelled differently .
5 braided packing material type which of these categories ?
A: Many types of woven material , according to the material of natural fibers, mineral fibers,barrier security seals synthetic fibers, ceramic and metal fiber four categories.
6 often said that self-healing is the kind of material ?
A: Flexible graphite .
Answer : Viton and NBR rubber seals are commonly used materials . As for petroleum based hydraulic fluids nitrile better compatibility , as a sealing material has good stability ,metal security seals the price is cheap, so in the hydraulic , pneumatic seal widely used. Viton is the best overall performance synthetic rubber sealing rubber . Carbon atoms, fluorine rubber, a fluorine atom primary key replacement, stable molecular structure . Its heat resistance, good chemical stability. Therefore, in high temperature applications and special occasions more media .
(2) What is the rubber material elongation ?
A: The elongation rate is the reciprocal of stiffness of a material index , the amount of materials used in the natural state of tension length ratio expressed as a percentage . Material allows elongation is not in permanent damage or permanent deformation occurs before the maximum elongation.
3 What rubber material breathable ?
A: refers to the gas permeability of the material in pneumatic sealing and vacuum -sealed material should be noted that this performance .
4 sealing material FPM, FKM What is the difference ?
Answer : FPM is ISO 1629 abbreviation of fluorine rubber , FKM Viton is ASTM 1418 in the name abbreviation . FPM and FKM are referring to the same kind of Viton, wording is different because the European and American English are spelled differently .
5 braided packing material type which of these categories ?
A: Many types of woven material , according to the material of natural fibers, mineral fibers,barrier security seals synthetic fibers, ceramic and metal fiber four categories.
6 often said that self-healing is the kind of material ?
A: Flexible graphite .
How to eliminate the external conditions on the effects of mechanical seals for pumps
The pump mechanical seal is used, not only to consider the mechanical seal itself, influencing factors, tamper evident seals but also to consider a variety of mechanical seals external factors .
1 large measure to eliminate channeling shaft
Rational design of axial force balancing device , eliminate the axial channeling . To meet this requirement , for multi- stage centrifugal pumps, ideal design is twofold: one is to balance the axial thrust bearing plate plus , the balance disc balance the axial force , the axial thrust bearing on the shaft for axial limit ; balancing drum plus the other is an axial thrust bearing , the balance drum axial force balance out the most , and the remaining axial force by thrust bearings bear , while the axial thrust bearing for the shaft axis to the limit . The second scheme is the key to the rational design of balancing drum so that it can really balance out most of the axial force. For other single-stage pump in a pump and other products, are designed to take some measures to ensure that the amount of the mechanical shaft seal channeling the required range.
(2) Measures to eliminate the axial force is too large
Rational design of axial force balance mechanism , so that it can truly and fully balance out the axial force to the mechanical wire seal to create a good condition. For some plants , petroleum, chemical and other fields important products , in the factory before the test must be done to detect and Taiwan and Taiwan issues and solve problems. Some pumps can be important to design a rotor axial measuring ring , on the size of the axial force at any time to monitor , identify problems and timely solutions.
1 large measure to eliminate channeling shaft
Rational design of axial force balancing device , eliminate the axial channeling . To meet this requirement , for multi- stage centrifugal pumps, ideal design is twofold: one is to balance the axial thrust bearing plate plus , the balance disc balance the axial force , the axial thrust bearing on the shaft for axial limit ; balancing drum plus the other is an axial thrust bearing , the balance drum axial force balance out the most , and the remaining axial force by thrust bearings bear , while the axial thrust bearing for the shaft axis to the limit . The second scheme is the key to the rational design of balancing drum so that it can really balance out most of the axial force. For other single-stage pump in a pump and other products, are designed to take some measures to ensure that the amount of the mechanical shaft seal channeling the required range.
(2) Measures to eliminate the axial force is too large
Rational design of axial force balance mechanism , so that it can truly and fully balance out the axial force to the mechanical wire seal to create a good condition. For some plants , petroleum, chemical and other fields important products , in the factory before the test must be done to detect and Taiwan and Taiwan issues and solve problems. Some pumps can be important to design a rotor axial measuring ring , on the size of the axial force at any time to monitor , identify problems and timely solutions.
2013年10月11日星期五
Heat pumps and cooling pump eight differences
Heat pumps and cooling pump eight differences are as follows :
A heat pump models are generally expressed by the letter R , cold oil pump with the letter J represents waterproof labels.
2 , heat pumps pump with vertical segmented , and cold pump pump with horizontal split , some heat pump to prevent the pump centerline structures.
3 , the heat pump orifice ring gap bigger. Cold oil pump is smaller.
4 , the average heat pump seal oil seal agencies note , and cold pump not inject .
5 , the heat pump timber multi- carbon steel , alloy steel , and cold pump can be made of cast iron .
6 , the heat pump bearings, bearing boxes, packing boxes mechanical seals require water cooling , and cold pump can not use .
7, the heat pump needs to warm up before the start , but with cold pump , the cooling pump is unnecessary .
8, the use temperature of 200 degrees Celsius for the cold pump, 200 degrees Celsius for the heat pump identification cable ties.
A heat pump models are generally expressed by the letter R , cold oil pump with the letter J represents waterproof labels.
2 , heat pumps pump with vertical segmented , and cold pump pump with horizontal split , some heat pump to prevent the pump centerline structures.
3 , the heat pump orifice ring gap bigger. Cold oil pump is smaller.
4 , the average heat pump seal oil seal agencies note , and cold pump not inject .
5 , the heat pump timber multi- carbon steel , alloy steel , and cold pump can be made of cast iron .
6 , the heat pump bearings, bearing boxes, packing boxes mechanical seals require water cooling , and cold pump can not use .
7, the heat pump needs to warm up before the start , but with cold pump , the cooling pump is unnecessary .
8, the use temperature of 200 degrees Celsius for the cold pump, 200 degrees Celsius for the heat pump identification cable ties.
Rotating cell to ring mounting method
Installation Instructions:
1 cusp requirements deburring, vehicle seals chamfering blunt or install seals case of thread, requiring additional protection to prevent damage to seals.
(2) Any rust , dirt , debris or foreign particles must be removed.
3 not allowed to use the tools with sharp corners .
4 Before installation , cylinder, rotary shaft and seals need to apply oil or grease . If grease, its composition does not contain solid additives ( such as molybdenum disulfide, zinc sulfide or the like ) .
5 . PTFE slip ring can be in oil or water heated to 80 ~ 120 ℃, PTFE slip ring expands , it is easier to install on the piston or rod .
Mounting shaft rotary Grameen circle :
Shaft rotation Grameen ring is usually installed in a closed groove :
1 . The first O-ring into the groove , while pressing the PTFE slip ring heart shape , but be careful to prevent breakage
(2) the state of the pressure on the slip ring PTFE O- ring , and then a rod ( usually with 10 ~ 15 °) direction of the arrow Flatten PTFE slip ring , to restore the original size security seals .
1 cusp requirements deburring, vehicle seals chamfering blunt or install seals case of thread, requiring additional protection to prevent damage to seals.
(2) Any rust , dirt , debris or foreign particles must be removed.
3 not allowed to use the tools with sharp corners .
4 Before installation , cylinder, rotary shaft and seals need to apply oil or grease . If grease, its composition does not contain solid additives ( such as molybdenum disulfide, zinc sulfide or the like ) .
5 . PTFE slip ring can be in oil or water heated to 80 ~ 120 ℃, PTFE slip ring expands , it is easier to install on the piston or rod .
Mounting shaft rotary Grameen circle :
Shaft rotation Grameen ring is usually installed in a closed groove :
1 . The first O-ring into the groove , while pressing the PTFE slip ring heart shape , but be careful to prevent breakage
(2) the state of the pressure on the slip ring PTFE O- ring , and then a rod ( usually with 10 ~ 15 °) direction of the arrow Flatten PTFE slip ring , to restore the original size security seals .
2013年10月9日星期三
Select two aspects of imported bearings mechanical seal structure
Bearing structure type mechanical seal selection is an important step in the design cycle , you must first be investigated : ① operating parameters of the medium pressure , temperature, shaft diameter and speed . ② the concentration of dielectric properties , viscosity, corrosion , with or without solid particles and fibrous impurities are easily vaporized or crystallization . ③ host work characteristics and environmental conditions continuous or intermittent operation ; mainframe installed in the indoor or outdoor ; atmosphere surrounding the nature and temperature changes. ④ host allowable leakage seal leakage direction ( internal leakage or leakage ) requirements ; life and reliability requirements. ⑤ host sealing structure or size. ⑥ operation and production process stability .
1, according to the operating parameters p, v, t Selection
Where p is the pressure of the medium at the sealed chamber , according to the size of the p-value can initially determine whether to select balanced structure and the degree of balance . NSK Bearings for medium viscosity, good lubricity , p0.8MPa, or low viscosity, poor lubricating medium , p0.5MPa when the structure is usually used unbalanced . p-value exceeds the above range , you should consider using balanced structure. When p> 15MPa , generally single face -balanced structure is difficult to achieve sealing requirements , then you can use multiple tandem seal .
Refers to the average diameter of the circumferential sealing surface velocity , depending on the value of the size of the elastic member to determine whether the rotation with the shaft , which uses a rotary spring or spring static structure , generally <20 ~ 30m / s in a rotary spring can be higher speed conditions, the rotating parts can lead to strong vibration unbalance mass , preferably spring stationary structure. If p and values are high, considering the selection of hydrodynamic structure.
t is the seal cavity medium temperature , FAG bearings based on t determine the size of secondary seal material, the sealing surface of the cooling method and its auxiliary systems. Temperature t in the range of 0 ~ 80 ℃ , secondary seal is usually chosen nitrile rubber O-ring ; -50 ℃ t <150 ℃, according to the strength of corrosive media , the choice of fluorine rubber, silicone rubber or Teflon molding packing ring: temperature < -50 or t150 ℃ , the rubber and PTFE will produce low or high temperature aging embrittlement , metal bellows structure can be used at this time . Medium turbidity higher than 80 ℃, in a sealed area is usually necessary to be considered at high temperatures , the cooling time must take appropriate measures .
Second, according to media characteristics selection less corrosive media
Usually use the built -in mechanical security seals , SKF bearing its face the stress state and the direction of media leaks than the external and reasonable. For strongly corrosive media , the more difficult the selection of the spring , the choice of external or PTFE bellows type mechanical seal , but generally only applicable p0.2 ~ 0.3MPa range.
Easy to crystallize , easy coagulation and high viscosity medium , large springs should be used rotating structure. Because small spring easily be blocked solids , high viscosity media make small spring axial compensation movement blocked.
Flammable, explosive, toxic media , in order to ensure that the media does not leak , you should use a sealing liquid ( liquid separation ) of the double-end structure .
Press the dielectric properties of the selected operating parameters and the structure is often only a preliminary program , INA Bearing ultimately determine the host must also consider the characteristics and the sealing of some special requirements. For example, the rocket engine seal life just a few minutes , but requires a short time absolutely does not leak .nylon cable ties Sometimes hosts on the ship in order to obtain a more efficient space , the size of the seal and mounting position are often made very demanding , and if the drain pump on submarines , submarine ups and downs in the process, the pressure varies widely and so on. In these cases , it is not the conventional structure of the selection criteria , and must be specially designed for the specific conditions , while taking the necessary complementary measures.
1, according to the operating parameters p, v, t Selection
Where p is the pressure of the medium at the sealed chamber , according to the size of the p-value can initially determine whether to select balanced structure and the degree of balance . NSK Bearings for medium viscosity, good lubricity , p0.8MPa, or low viscosity, poor lubricating medium , p0.5MPa when the structure is usually used unbalanced . p-value exceeds the above range , you should consider using balanced structure. When p> 15MPa , generally single face -balanced structure is difficult to achieve sealing requirements , then you can use multiple tandem seal .
Refers to the average diameter of the circumferential sealing surface velocity , depending on the value of the size of the elastic member to determine whether the rotation with the shaft , which uses a rotary spring or spring static structure , generally <20 ~ 30m / s in a rotary spring can be higher speed conditions, the rotating parts can lead to strong vibration unbalance mass , preferably spring stationary structure. If p and values are high, considering the selection of hydrodynamic structure.
t is the seal cavity medium temperature , FAG bearings based on t determine the size of secondary seal material, the sealing surface of the cooling method and its auxiliary systems. Temperature t in the range of 0 ~ 80 ℃ , secondary seal is usually chosen nitrile rubber O-ring ; -50 ℃ t <150 ℃, according to the strength of corrosive media , the choice of fluorine rubber, silicone rubber or Teflon molding packing ring: temperature < -50 or t150 ℃ , the rubber and PTFE will produce low or high temperature aging embrittlement , metal bellows structure can be used at this time . Medium turbidity higher than 80 ℃, in a sealed area is usually necessary to be considered at high temperatures , the cooling time must take appropriate measures .
Second, according to media characteristics selection less corrosive media
Usually use the built -in mechanical security seals , SKF bearing its face the stress state and the direction of media leaks than the external and reasonable. For strongly corrosive media , the more difficult the selection of the spring , the choice of external or PTFE bellows type mechanical seal , but generally only applicable p0.2 ~ 0.3MPa range.
Easy to crystallize , easy coagulation and high viscosity medium , large springs should be used rotating structure. Because small spring easily be blocked solids , high viscosity media make small spring axial compensation movement blocked.
Flammable, explosive, toxic media , in order to ensure that the media does not leak , you should use a sealing liquid ( liquid separation ) of the double-end structure .
Press the dielectric properties of the selected operating parameters and the structure is often only a preliminary program , INA Bearing ultimately determine the host must also consider the characteristics and the sealing of some special requirements. For example, the rocket engine seal life just a few minutes , but requires a short time absolutely does not leak .nylon cable ties Sometimes hosts on the ship in order to obtain a more efficient space , the size of the seal and mounting position are often made very demanding , and if the drain pump on submarines , submarine ups and downs in the process, the pressure varies widely and so on. In these cases , it is not the conventional structure of the selection criteria , and must be specially designed for the specific conditions , while taking the necessary complementary measures.
Pump Mechanical Seal Overhaul Mistakes
1 greater the amount of spring compression seal better. In actual fact , the spring compression excessive friction can cause rapid wear , instantly burning ; excessive compression of the spring to lose the ability to adjust the ring face , resulting in seal failure.
2 ring seal Fig tight as possible . In fact, ring seals tight harm than good. First exacerbate inter- ring and sleeve wear, premature leakage ; Second, increasing the axial adjustment ring , the resistance movement , frequent changes in operating conditions can not make timely adjustments ; Third spring fatigue easily damaged ; four is to make the ring seal deformation, affecting the sealing effect.
3 stationary ring seal tight as possible . Stationary ring seals basically at a standstill , the effect will be relatively tight seal better, but too tight is harmful. One cause static ring security stickers due to excessive deformation, affecting the sealing effect ; Second, the majority of graphite stationary ring material , generally more brittle , excessive force can easily cause fragmentation ; three is to install , difficult to remove , easy to damage the stationary ring .
4 Impeller lock nut tight as possible . Mechanical seal leakage , the leakage between the sleeve and the shaft ( shaft between the leak ) is relatively common . Generally, the impeller shaft between the leak is not locking the lock master , in fact, lead to leakage between axes many factors , such as the failure of inter-axis pad , offset , there are impurities between axes , with the shaft and sleeve at a larger shape bit error , the contact surface damage , there is a gap between the shaft parts , threaded shaft is too long , and this will lead to leakage between the shafts . Lock nut locking pad between axes can only lead to excessive premature failure , contrary moderate lock locked mother , so that the shaft between the pads always maintain a certain degree of compression flexibility in operation will be automatically timely lock nut locking , so that the shaft is always in a good inter- the sealed state .
5 The new better than the old . In contrast, using the new mechanical seal better than the old , but the new mechanical seal quality or choice of material is not the time , with the larger size of the error will affect the sealing effect ; and permeability in the polymerization medium, the stationary ring without excessive wear, or not to replace as well. Because static ring stationary ring seat for a long time in a quiescent state , the polymer and impurities deposited as a whole, played a good seal.
6 overhaul better than not split tamper seal. Once the mechanical seal leakage will be eager to overhaul , in fact , sometimes sealed and not damaged , simply adjust the working conditions or the seals can be adjusted to eliminate leakage. This way to avoid waste and to verify their ability to judge the fault has accumulated experience in maintenance to improve the quality of maintenance .
2 ring seal Fig tight as possible . In fact, ring seals tight harm than good. First exacerbate inter- ring and sleeve wear, premature leakage ; Second, increasing the axial adjustment ring , the resistance movement , frequent changes in operating conditions can not make timely adjustments ; Third spring fatigue easily damaged ; four is to make the ring seal deformation, affecting the sealing effect.
3 stationary ring seal tight as possible . Stationary ring seals basically at a standstill , the effect will be relatively tight seal better, but too tight is harmful. One cause static ring security stickers due to excessive deformation, affecting the sealing effect ; Second, the majority of graphite stationary ring material , generally more brittle , excessive force can easily cause fragmentation ; three is to install , difficult to remove , easy to damage the stationary ring .
4 Impeller lock nut tight as possible . Mechanical seal leakage , the leakage between the sleeve and the shaft ( shaft between the leak ) is relatively common . Generally, the impeller shaft between the leak is not locking the lock master , in fact, lead to leakage between axes many factors , such as the failure of inter-axis pad , offset , there are impurities between axes , with the shaft and sleeve at a larger shape bit error , the contact surface damage , there is a gap between the shaft parts , threaded shaft is too long , and this will lead to leakage between the shafts . Lock nut locking pad between axes can only lead to excessive premature failure , contrary moderate lock locked mother , so that the shaft between the pads always maintain a certain degree of compression flexibility in operation will be automatically timely lock nut locking , so that the shaft is always in a good inter- the sealed state .
5 The new better than the old . In contrast, using the new mechanical seal better than the old , but the new mechanical seal quality or choice of material is not the time , with the larger size of the error will affect the sealing effect ; and permeability in the polymerization medium, the stationary ring without excessive wear, or not to replace as well. Because static ring stationary ring seat for a long time in a quiescent state , the polymer and impurities deposited as a whole, played a good seal.
6 overhaul better than not split tamper seal. Once the mechanical seal leakage will be eager to overhaul , in fact , sometimes sealed and not damaged , simply adjust the working conditions or the seals can be adjusted to eliminate leakage. This way to avoid waste and to verify their ability to judge the fault has accumulated experience in maintenance to improve the quality of maintenance .
2013年10月8日星期二
Reactor with a mechanical seal principle introduced
Mechanical seal is by one pair or several pairs perpendicular to the axis relative to the sliding face in the fluid pressure and compensation institutions elastic ( or magnetic ) to keep under seal affixed to achieve the merger with auxiliary shaft seal leakage resistance device .
Common mechanical seal structure consists of stationary ring ( stationary ring ) 1, the rotating ring ( ring ) 2, the elastic element 3, the spring seat four , set screws 5 , 6 secondary seal rotating ring and the stationary ring seal 8 and other auxiliary components , anti-rotation pin 7 is fixed to prevent the gland 9 stationary ring is rotated . Rotating ring and the stationary ring often also according to whether they have the ability to compensate for axial cyclic or compensation is also referred to as compensation .
Mechanical seal possible leakage of fluid channels are A, B, C, D four channels.
C, D leakage channels are stationary ring and the gland , the gland seal between the housing , the two are static seal .ss cable ties B channel between the rotary shaft sealing ring and , when Friction and wear , it can follow the compensation ring only for a small amount of movement in the axial direction , in fact, still a relatively static seal .
Therefore, these leak paths are relatively easy closure. The most commonly used static sealing rubber O-ring or PTFE V-ring , and as compensation or stationary rotating ring ring ring secondary seal , sometimes using both elastic elements feature rubber, PTFE or metal bellows structures.
A channel is a rotating ring and the stationary ring opposite end faces sliding Lamination dynamic seal , it is the mechanical seal device of the main seal , mechanical seal in determining the performance and life of the key. Thus , the processing requirements of the seal face is high , while the sealing end faces in order to maintain the necessary lubrication film , the system must be strictly the end surface of the cavity pressure per unit area , the pressure is too large, difficult to form a stable lubricating film , will accelerate the end wear ; pressure is too small , increase of leakage . Therefore, to obtain good sealing performance and enough life , in the design and installation of mechanical seals , we must ensure that the pressure per unit area of face value in the most appropriate range.
Mechanical seal with relatively soft packing seal , has the following advantages:
① reliable sealing in a long period of operation, the sealed state is very stable, very small leakage , wire seals according to rough statistics, the leakage is typically only soft packing seal 1/100 ;
② long life in oil, aqueous medium, generally up to 1 to 2 years or more, usually in the chemical medium can be more than six months ;
③ friction small power consumption of the mechanical seal is only soft packing seal friction power of 10% to 50%.
Common mechanical seal structure consists of stationary ring ( stationary ring ) 1, the rotating ring ( ring ) 2, the elastic element 3, the spring seat four , set screws 5 , 6 secondary seal rotating ring and the stationary ring seal 8 and other auxiliary components , anti-rotation pin 7 is fixed to prevent the gland 9 stationary ring is rotated . Rotating ring and the stationary ring often also according to whether they have the ability to compensate for axial cyclic or compensation is also referred to as compensation .
Mechanical seal possible leakage of fluid channels are A, B, C, D four channels.
C, D leakage channels are stationary ring and the gland , the gland seal between the housing , the two are static seal .ss cable ties B channel between the rotary shaft sealing ring and , when Friction and wear , it can follow the compensation ring only for a small amount of movement in the axial direction , in fact, still a relatively static seal .
Therefore, these leak paths are relatively easy closure. The most commonly used static sealing rubber O-ring or PTFE V-ring , and as compensation or stationary rotating ring ring ring secondary seal , sometimes using both elastic elements feature rubber, PTFE or metal bellows structures.
A channel is a rotating ring and the stationary ring opposite end faces sliding Lamination dynamic seal , it is the mechanical seal device of the main seal , mechanical seal in determining the performance and life of the key. Thus , the processing requirements of the seal face is high , while the sealing end faces in order to maintain the necessary lubrication film , the system must be strictly the end surface of the cavity pressure per unit area , the pressure is too large, difficult to form a stable lubricating film , will accelerate the end wear ; pressure is too small , increase of leakage . Therefore, to obtain good sealing performance and enough life , in the design and installation of mechanical seals , we must ensure that the pressure per unit area of face value in the most appropriate range.
Mechanical seal with relatively soft packing seal , has the following advantages:
① reliable sealing in a long period of operation, the sealed state is very stable, very small leakage , wire seals according to rough statistics, the leakage is typically only soft packing seal 1/100 ;
② long life in oil, aqueous medium, generally up to 1 to 2 years or more, usually in the chemical medium can be more than six months ;
③ friction small power consumption of the mechanical seal is only soft packing seal friction power of 10% to 50%.
Chemical pump mechanical seal options introduced
No leakage is always the pursuit of chemical equipment , it is this requirement led to the application of magnetic pump expanding . However, truly no leakage is still a long way to go, such as magnetic pump containment shell life issues, pitting the material problems of static trailer seals sealing reliability issues and so on. Now on some basic aspects of seal briefly as follows:
A seal forms for static sealing , it is usually only two forms of gaskets and seals , and O-ring seals Youyi most widely ; For dynamic sealing , chemical pumps rarely used packing seal, mechanical seal based , mechanical seals have single face and double face , balanced and unbalanced type of points , balanced for high pressure sealing medium ( usually refers to pressure greater than 1.0MPA), double end mechanical seal is mainly used for high temperature , easy to crystallize , there viscosity, containing particles and toxic volatile media , double end mechanical seal should insulating liquid is injected into the sealed chamber , the pressure is generally higher than the medium pressure 0.07 ~ 0.1MPA.
2 , the sealing material chemical magnetic pump static sealing materials commonly used Viton, PTFE used under special circumstances materials ; mechanical seal ring material movement configuration is more critical , and not on the best carbide cemented carbide ,vehicle seals high prices on the one hand , the hardness difference between the two is not too unreasonable , so it is best treated differently according to media characteristics .
A seal forms for static sealing , it is usually only two forms of gaskets and seals , and O-ring seals Youyi most widely ; For dynamic sealing , chemical pumps rarely used packing seal, mechanical seal based , mechanical seals have single face and double face , balanced and unbalanced type of points , balanced for high pressure sealing medium ( usually refers to pressure greater than 1.0MPA), double end mechanical seal is mainly used for high temperature , easy to crystallize , there viscosity, containing particles and toxic volatile media , double end mechanical seal should insulating liquid is injected into the sealed chamber , the pressure is generally higher than the medium pressure 0.07 ~ 0.1MPA.
2 , the sealing material chemical magnetic pump static sealing materials commonly used Viton, PTFE used under special circumstances materials ; mechanical seal ring material movement configuration is more critical , and not on the best carbide cemented carbide ,vehicle seals high prices on the one hand , the hardness difference between the two is not too unreasonable , so it is best treated differently according to media characteristics .
2013年10月7日星期一
Asphalt pump mechanical seal repair errors introduced
1, the ring seal tight as possible . Asphalt pump stationary ring seals basically at a standstill , the effect will be relatively tight seal better, but too tight is harmful.
One cause static ring seals due to excessive building deformation, affecting the sealing effect ; two is mostly static ring material with graphite . Generally more brittle , excessive force can easily cause fragmentation ; three is to install , difficult to remove , easy to damage the stationary ring .
2, the new better than the old . Relatively new asphalt pump mechanical seal better than the old , but the new mechanical seal quality or choice of material is not the time , with the larger size of the error will affect the sealing effect : and permeability in the polymerization medium, such as non- stationary ring excessive wear, or not replaced as well. Because static ring stationary ring seat for a long time in a quiescent state , the polymer and impurities deposited into one. Played a better Plastic seal.
3 , static overhaul than never dismantle good, asphalt pump mechanical seal leakage will occur once the rush to overhaul . In fact , sometimes sealed and not damaged , simply adjust the working conditions or the seals can be adjusted to eliminate leakage. This way to avoid waste and to verify their ability to judge the fault has accumulated experience in maintenance to improve the quality of maintenance .
4 , impeller lock nut tight as possible . Asphalt pump mechanical seal leakage , the leakage between the sleeve and the shaft ( shaft between the leak ) is relatively common , generally believed that the impeller shaft lock nut ask leak did not lock their buying lead to leakage between axes many factors , If lapse between axes pad , offset shaft ask there impurities, with the shaft and sleeve at a larger form and position errors , contact surface damage. shaft there is a gap between the various components ; shaft threaded shaft is too long , and this will lead to between the leak. Lock nut locking pad between axes can only lead to excessive premature failure , contrary moderate lock locked mother, so always keep a pad shaft ask Piece Goods compression elasticity, in operation lock nut locking automatically timely , so that the shaft is always in a good inter- the sealed state .
5 , ring seals tight as possible , in fact, detrimental tight ring seals . First exacerbate the wear ring and sleeve between leakage ; Second, increasing the axial adjustment ring , the resistance movement , frequent changes in operating conditions can not make timely adjustments ; Third spring fatigue easily damaged : four is to make the move ring security stickers deformation, affecting the sealing effect.
6, the greater the amount of spring compression sealing the better . Its buy Otherwise, spring compression excessive friction can cause rapid wear , instantly burning ; excessive compression of the spring to lose the ability to adjust the ring face , resulting in seal failure.
One cause static ring seals due to excessive building deformation, affecting the sealing effect ; two is mostly static ring material with graphite . Generally more brittle , excessive force can easily cause fragmentation ; three is to install , difficult to remove , easy to damage the stationary ring .
2, the new better than the old . Relatively new asphalt pump mechanical seal better than the old , but the new mechanical seal quality or choice of material is not the time , with the larger size of the error will affect the sealing effect : and permeability in the polymerization medium, such as non- stationary ring excessive wear, or not replaced as well. Because static ring stationary ring seat for a long time in a quiescent state , the polymer and impurities deposited into one. Played a better Plastic seal.
3 , static overhaul than never dismantle good, asphalt pump mechanical seal leakage will occur once the rush to overhaul . In fact , sometimes sealed and not damaged , simply adjust the working conditions or the seals can be adjusted to eliminate leakage. This way to avoid waste and to verify their ability to judge the fault has accumulated experience in maintenance to improve the quality of maintenance .
4 , impeller lock nut tight as possible . Asphalt pump mechanical seal leakage , the leakage between the sleeve and the shaft ( shaft between the leak ) is relatively common , generally believed that the impeller shaft lock nut ask leak did not lock their buying lead to leakage between axes many factors , If lapse between axes pad , offset shaft ask there impurities, with the shaft and sleeve at a larger form and position errors , contact surface damage. shaft there is a gap between the various components ; shaft threaded shaft is too long , and this will lead to between the leak. Lock nut locking pad between axes can only lead to excessive premature failure , contrary moderate lock locked mother, so always keep a pad shaft ask Piece Goods compression elasticity, in operation lock nut locking automatically timely , so that the shaft is always in a good inter- the sealed state .
5 , ring seals tight as possible , in fact, detrimental tight ring seals . First exacerbate the wear ring and sleeve between leakage ; Second, increasing the axial adjustment ring , the resistance movement , frequent changes in operating conditions can not make timely adjustments ; Third spring fatigue easily damaged : four is to make the move ring security stickers deformation, affecting the sealing effect.
6, the greater the amount of spring compression sealing the better . Its buy Otherwise, spring compression excessive friction can cause rapid wear , instantly burning ; excessive compression of the spring to lose the ability to adjust the ring face , resulting in seal failure.
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