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.
high security bolt seals
high security bolt seals
2013年11月22日星期五
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.
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