Food packaging seal performance test method has been improved

Food vacuum packing sealing performance and overall internal gas residues directly affect the shelf life of foods and tastes change, is relevant companies must pay attention and control indicators. Sealing performance sealing reliability refers to the packaging through which the test can be padlock seal sealed to ensure the integrity of the product packaging, vacuum packaging the principle determines the overall tightness, and the importance of the internal gas residues.
Sealing performance testing methods commonly used in two ways: The first is to use the seal tester; using the vacuum principle, according to national standards are in-30kpa,-50kpa,-70kpa,-90kpa 0.5 min, mainly for vacuum packaging observed after the test sample recovery. Of course, the above method is to use the principle of visual method is a qualitative test mode. The second method is the use of the principle sealing pressure test equipment, by injecting a gas to the interior of the package to monitor pressure changes to determine its sealing properties; This method is clearly a quantitative test methods, but it is destructive to the sample test, test for vacuum packaging with certain limitations.
Recently, the launch of the latest vacuum packaging residual oxygen analyzer solves the above two principles device when tested for vacuum packaging problems. Test, the first chamber of the vacuum chamber filled with water, cover seal plate, and then the slow water metering cylinder to the designated area, the upper cover, compress the wire seals plate, while the test cavity is evacuated to the specimen swelling, and finally through analysis and related level calculated the amount of gas remaining in packaging; both quantitative measurement can be accurately vacuum packaging various types of food, packaging containers sealing performance.

Common sense interpretation seal doors and windows

Door seals are mainly used in steel doors, aluminum doors and windows, wooden doors and windows and other architectural decorative doors and windows. The main role of dust, insects, water, noise and sealing. Steel doors and windows on the market are generally sealing strip PVC, modified PVC, EPDM elastomer seal, silicone and other materials out of shape.
Doors and windows sealed Features
Steel doors and windows high security seals is used widely in recent years, a new generation of windows and doors, it is more common seal doors and windows have better corrosion resistance, weather resistance, noise insulation. Steel doors and windows sealed, smooth surface, not only has excellent waterproof seal performance, but also plays a beautiful decorative effect. In the selection, the general requirements of the manufacturers have chosen a higher EPDM rubber or thermoplastic EPDM rubber.
Ethylene propylene diene monomer (EPDM) Product Key Features: Non-toxic, environmental protection, anti-aging, high temperature, stable performance, summer, winter can maintain good performance.
1, the steel skeleton three composite, not easily deformed contraction, ruggedly good sealing
2, doors, windows, curtain wall metal security seal, the product has good elasticity, resistance to migration, can effectively block the noise, dust, wind and rain.

Material rubber sealing profiles

China air with special rubber sealing profiles used by the rubber material of nitrile rubber prior to the widespread use of silicone rubber, fluorosilicone rubber , rubber material functional direction.
Currently China Airlines with special rubber sealing profiles used in various types of sealing profiles to neoprene and nitrile rubber and the most widely used . And rubber , while having good strength and excellent oil resistance , but its impatience sunlight , machined rubber profiles in flight conditions often occur after a period of time cracking phenomenon , profiles the life and the use of safety are compromised .
Europe and other countries, new types of aircraft designed multi- use silicone rubber as its aviation special rubber coloured cable ties profiles of the main material . Silicone rubber temperature field performance, while also superior resistance to weather aging properties of nitrile rubber and other materials , but its strength is low , but do not have the fire-retardant requirements. Silicone rubber sealing profiles to improve strength and wear resistance , the use of the compound used more and fabric materials .
Most aircraft parts are resistant to burning requirements, silicone rubber material with the added need to make the processing of various types of flame retardant sealing profiles to achieve resistance to combustion requirements. Flame retardants are widely used in the past , aluminum hydroxide, decabromodiphenyl ether , aluminum hydroxide as an aftereffect flame retardant, requires a large amount of filler in order to achieve better flame-retardant effect , would seriously undermine the filling material mechanical properties. DecaBDE as halogen-containing flame retardant effect of the fine , but its release toxic gases when burned difficult to meet the environmental requirements of the aviation industry now .
In order to meet the requirements , the domestic enterprises to use composite materials to improve flame retardant silicone rubber profiles , through the use of new and efficient platinum -based flame retardant to achieve efficient and environmentally friendly flame retardant dual requirements . According to the literature reports, foreign countries have developed a new reactive flame retardant, can pass with minimal amount of combustion flame retardant chemical reactions to achieve results.
For aviation development, new aviation with special rubber tamper seal profiles even require electromagnetic shielding , high-temperature resistant , thermal conductivity , anti- erosion and other special requirements .

Sealing strip doors and windows sealed in the field of the use of

Windows layering tops into the glass sealing strip and two kinds. Want the whole story window seal tie wraps must be done within a fan on layering and wearing a sealing strip, the only way to make glass and box fan finer , thus ensuring the tightness of windows .
Inspector said window frame and wall junction should be done sealants , handling should be smooth and straight . Between the glass and the window frames are tight rubber seal , not only to the aesthetic problem , but also affect the window glass sealing effect.
Windows sealed condition inspection points include sash seal sealing effect , sash indicative seal sash and window frames usually in contact at the mosaic . Inspection windows batten main points are: seal surface should be smooth, flat , straight , interfaces to meticulous, neat .

The method of techniques to enhance type plug

Enhance type plug has a variety of structural forms, enhance type plug according to the sealing surface of the material is divided into two kinds of soft seal and hard seal. The basic principle is to open up the cock, cocks and then turn 90 degrees to the process valve is fully open and valve sealing surface to reduce friction; close the valve when the cock is rotated by 90 degrees to the closed position and then decreased with body seal surface contact to Plastic seal.
1, double sealed to enhance type plug
Double sealed to enhance type plug with soft sealing structure. Cock body is a combination of three panels cylindrical plug body, set on both sides of the rubber plate sealing surface, the intermediate cylindrical wedge plug.
Open the valve actuator to make cocks rise, driven by both sides of the plate collapsed, and the combination of the plug body from the valve sealing surface, then drive plug body is rotated 90 degrees to the valve fully open position.
Close the valve drive mechanism so that rotation of the plug body 90 degrees portfolio to the closed position, and then push down the plug body, both sides of the plate is no longer in contact with the bottom of the body down the middle wedge plugs continue to decline, pushing through the beveled side plates mobile phase inlet and outlet, so that side of the soft sealing surface in contact with the valve sealing surface is compressed to numbered seals.
Double sealed to enhance type plug has dual obstruction and discharge function, the valve has a pressure balance device, to prevent abnormal pressure system, and can reduce the valve opening and closing moments of resistance. Since the metal surface after sealing ring is compressed in contact with each other, the valve has a fire safety features. Very convenient maintenance of the valve, the valve body can be made without removing the case from the pipeline, the bottom of the cap body by removing the side panels can be removed from the body replacement. It is also widely used in petroleum, natural gas, metallurgy, mining, gas engineering, textile, marine terminals, food, and water treatment and other industries to make adjustments, opening and closing the pipeline fluid use.

Doors and windows seal leakage is not necessarily a good question without

Window air leakage
>> One reason: poor material
Now the windows broken bridge insulation material to aluminum, steel windows for the mainstream, aluminum doors and windows have been sealed because of their poor performance will be phased out. But even purchased a plastic-steel windows and windows broken bridge, experts suggest that it should pay attention to materials.
"Whether the window air leakage great relationship with the material." Decoration industry Beijing Branch Director of Engineering Huzeng Guang said that if the material is poor, windows of deformation occurs two or three years, once deformed, the sealing performance poor, it leakage will occur, so it also reminds owners in the purchase of the windows to be extra careful material.
Solution: You can only find windows manufacturers to solve.
>> Two reasons: installed in place even if the material has excellent windows, the installation process is not in place to determine if the window is an important factor in air leakage. First, the windows must Yasumasa, otherwise use the window may appear after a period of time more and more crooked windows circumstances, the gap between the window frame and the wall also will be increasing, air leakage inevitable.
Secondly, the reporter has learned that the windows of the installation, you need to hit styrofoam filling the gap between the window frame and the wall. Styrofoam be cured, and then in the sash around evenly with sealant, both to prevent rainwater from the window and wall mounting gap penetrate indoors, but also to prevent air leakage. But also in the internal and external sided sizing windows, but Hu Zengguang introduction, some workers the easy way, just inside a plastic, or gluing several points inside, Mifengbuyan. Even outside playing styrofoam, but a year or year and a half or so will chalking, summer leaks, leakage situation occurs in winter. In addition, when the renovation, home improvement workers found Mifengbuyan sash with Qiangfeng gap will fill the putty from the inside, but a long time, there will be a remote seam, causing leakage.
Solution: In the first case have to find windows manufacturers. If only the windows inside the glue did not play well, the gap is relatively small, it can affix themselves Masking toward the gap in the Fixed Length plastic seal sealant can be marked; external glue if there is a problem you need to contact the workers to operate it.
>> Three reasons: not to force windows accessories Another important reason is that air leakage sealing fittings out of order. The most common is the seal aging crack, a direct result of poor performance window seals; there is a foam rubber is too soft, the use of powder occurs after a few years, resulting in the gap between the window frame and the wall becomes large, resulting in air leakage.
Solution: Can you change the bolt security seals, using EPDM rubber is better, or poorer quality rubber strips can; if they can not operate, to find street shop workers doing steel window replacement cost will not too much. As for the foam, need to find workers to operate, styrofoam cured, the landlord can tweak their look, struggling to pinching the quality is better.

Analytical advantages of spiral seal

Advantage
1, spiral seal is a contactless releasable cable tie Lane, and allows a greater sealing gap, the solid-phase friction does not occur, the working life of up to several years, and easy maintenance.
2, the spiral sealing a "dynamic seal", which relies on the establishment sealed shaft power consumption state. Shaft sealing portion of the power to overcome the friction within the gap, and the other part of the direct pressure head for generating a centrifugal pumping, thus only medium shade leak.
3, screw seal for gas medium conditions. Because spiral gap can be filled with viscous fluid into liquid gas phase conditions.
4, the screw seal for low pressure working conditions (pressure less than 1 ~ 2MPa). Then a small amount of gas media leaks, cable sealing liquid (ie viscous liquid) can achieve zero leakage. Without sealing liquid cooling, simple structure.
5, in addition to as centrifugal pumps and screw sealing pressure centrifugal compressor shaft seals can also be used as a dust seal.

Introduction shaker seal species

Usually based on the different characteristics of the material, you can choose to use three different materials vibration sieve ring, namely: rubber seals, silicone seals, polyurethane barrier seals. These three rings have different characteristics, according to material properties, the right choice ring, can extend the seal life, effectively reduce the production costs.
1, rubber seals
Rubber seals are the most commonly used equipment vibration sieve seal parts, mainly because of its low cost, stable performance, but such as filtering material is corrosive, high temperature, big oil and other characteristics, the rubber seal is not as useful the. Usually no special materials such as user requirements, shaker vibration sieve manufacturers have opted for the factory installed rubber seals.
2, silicone seals
Silicone seals relatively high cost, but with a chemically stable silicone seals, thermal stability, adsorption properties, relatively high mechanical strength, etc., such as the user has the relevant characteristics of the material selection, choose silicone seal laps.
3, polyurethane seals
Vibration sieve polyurethane Cable tie are the most infrequently used equipment seals, mainly due to higher cost. Polyurethane seals with oil, corrosion resistance, high temperature and other characteristics, screening materials with relevant features users should choose to install polyurethane seals.

Fermented soft sealing valve should be adopted

Valves are the most used in the fermentation equipment ancillary equipment, which is the most used cut-off valve. Sealing valve on the media can be divided into four, namely nominal level, low leakage level, steam level and atomic level. Nominal level and low leakage level seal for valve closure requirements are not strict, for example, used to control the flow rate of the valve. Steam level sealing for steam and most other industrial valve seat, stem and body connection portion of the seal. Atomic level meter seal for sealing medium demanding applications, such as spacecraft and nuclear power equipment. Since the fermentation industry using high-temperature steam sterilization equipment for fermentation, so the valve sealing requirements of the media is a steam-tight.

Since the valve open during fermentation frequent often affected by corrosion, erosion and cavitation damages, so the valve vice structure, that contact between the valve seat and closure member for closing part of the selection is more critical. Vice-sealing valve structure divided into soft seal and hard seal two kinds. Hard seal structure sealing seat and closed by the occurrence of tiny pieces of plastic deformation squeeze each other to form a closed circular sealing contact line. Although such valve sealing effect in the application of the initial well, but more frequently fermentation valve open, easy to wear of the contact wire previously formed, or leaving the sealing surface of the pipe indentation dirty and damage. The seal of the sealing structure of the elastic deformation is small, the formation of new sealing contact line is very difficult, so long-term use may cause valve leakage, the fermentation failure. Soft sealing valve closure member generally use soft pads, the use of large plastic deformation gasket forming an annular sealing contact with a wide belt, to add plug sealing surface uneven, to eliminate the gap to form a seal. Its precision generally do not ask, if there are special requirements, body material can be stainless steel, soft wire seal off pieces with replaceable PTFE gasket, so that can be changed frequently to ensure that the valve PTFE gasket tightness

Resolution valve leakage and valve sealing performance factors

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 2008, July 1, 2009 began implementation of national standards GB/T13927-2008 "industrial valve pressure test." This standard is used with reference to the international standard ISO5208-2007 "Industrial valves valve pressure test" develop and the other is issued by the Ministry of Machinery Industry JB/T9092-1999 "valve testing and inspection," This standard is referenced to meet API598- 1986 "valve inspection and test" developed. GB/T13927-2008 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 indicative seals leakage than the inner seal more important. Therefore, the valve sealing performance should lead to the manufacturer's attention.
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 bolt seals 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, the sealing pressure than decreases, but also make the possibility of leakage increases. Therefore, the increase can not be unlimited sealing surface width.

Concrete sealer absolute advantage

First permanent increase strength and hardness: sealed concrete curing agent, curing the composition to make the concrete into a hard solid, forming a three-dimensional network structure, thereby increasing the density of the concrete, strength and hardness, and greatly improves the wear of concrete capability. Pink light after a smooth surface, will produce marble as beautiful sheen; through concrete sealer treated concrete, than the untreated, completely cured concrete compressive strength at 30 days after experimental determination, strength increases more than 30% and may vary time growth continued to increase intensity.

According to the introduction, and it permanently sealed, impermeability: concrete sealer used only once, and concrete that is subject to conservation role in the life cycle is permanently pull tight straps sealed and resistant to any oil and other contaminants; permanently cured concrete : concrete sealer to make the new concrete floor, inhibit minor cracks and temperature cracks, when construction for newly completed after proper watering and the solid concrete, concrete sealer and concrete composition of a chemical reaction substances, concrete sealer will retain the hydration process is extremely important for water conservation and consistency of concrete.

In addition it does not produce dust Permanent: sealed concrete curing agent and silicate concrete chemical reaction can be permanently sealed concrete curing agent to eliminate voids released from the surface of the concrete particles, thereby preventing from the gray; superior combination of Abilities: By eliminating the adverse combination of the concrete surface salts prepared surface more conducive to painting, waterproofing materials, combined with the use of agents and flooring materials; save a lot of repair and maintenance costs: According to experts, the concrete truck seal sealer treatment off the ground without waxing, only occasionally with soap and water or mopping the floor.

Selection of raw materials hollow door sealing performance is important

1, the total timber frame strength requirements should be easy to produce good insulation properties but also easy to make all kinds of shape recovery and are environmentally friendly.
2, promote the use of double sealed insulating glass and laminated glass with colored plastic polysulfide do spacer insulating glass insulating glass structure should be used if continuous angled corners pluggable in the joints must be sealed with butyl rubber . high security cable seals Single-sealed insulating glass with silicone rubber is unavailable to do the second sealed insulating glass is also undesirable because they are relatively short life.
3, the glass should promote the use of hollow glass and in the North should promote the use of Low-E insulating glass type. Radiant heat of the sun in the south dominated areas should promote the use of sun coated glass. Developed countries have basically not a single glass and white glass because they are not conducive to saving and improving the living environment.
4, another so-called Shuangbo not available. Some window type in order to reduce the heat transfer coefficient but also low price with a double glass that separates the two-story glass or ordinary adhesive seal mounted on the window without clicking zeolite sucked moisture is only single-channel seal. Generally intolerant aging sealant will not take long into the gray dust and can not wipe the affected eye very unsightly. Because that the use made of plastic insulating glass polysulfide insulating glass Cable tie sealing if only a single channel, then seal life is also just five glass curtain wall specification is expressly forbidden to use not to mention the ordinary sealant sealant even shorter its life the. Construction "project is the most critical aspect of life that is the durability issue. Use this Shuangbo only a temporary expedient very undesirable.

Rubber seal characteristics and application

Rubber sealing strip English name: rubbersealstrip. Rubber seal suggests that it is made of rubber production. Mainly used in automobiles, machinery, doors, windows and other areas, to prevent dust, insects, water, fixed, noise, vibration and sealing effect.

First, the rubber plastic seal of the features:

1, non-toxic, environmentally friendly, excellent aging resistance, high temperature resistance and chemical resistance properties of chemical drugs, has good flexibility and resistance to deformation, long-term use will not crack or deform at -50 degrees to 120 degrees can maintain its original between high sealing performance, has been cars, doors and windows, mechanical, electronic, electrical cabinets and other manufacturing industries widely used.

2, different shapes, different materials, or cold, heat, foam and other requirements with specific properties of products, can meet the needs of design and use.

Second, the rubber printed cable ties Typical applications:

1, used in steel doors, aluminum doors and windows, wooden doors and windows and other architectural windows and doors, the main role of dust, insects, water, noise, seals, etc.

2, the application of the doors in the door frames, side windows, front and rear windshield, hood and trunk lid, play a waterproof, dustproof, sound insulation, compartment temperature, shock absorption, decorative role.

3, used in electrical cabinet seal, which has a good sealing, waterproof, fire, insects, wind, every light, crash, and long service life characteristics.

Door seal system development trend

With the appearance of the body and sealing performance requirements are high, and the sealing strip manufacturing process and die level, body wire seal sealing systems presents some new design trends.

1 do for parting doors sealed, not only can reduce wind noise and can achieve a better appearance.
2 seal increasingly high degree of integration, there are many designs to triangular windows, triangular window guide rail and glass sealing strip made of one, some even outside the window sill seal also integrate them to form a part, thus reducing the generating a plurality of one-piece matching the size of the deviation, to improve the efficiency of assembly, and better appearance.
3 Energy saving and environmental requirements of the sealing strip will be more emphasis on the design, the conventional pull tite seals materials used in the vulcanized rubber is not conducive to recycling waste, a new material TPE / TPV sealing sectors are to be applied to promote easy achieve recycling, and its density is smaller than rubber, can reduce the weight of the sealing strip.

Please note that check the car tightness

Summer rain, the most prone to the problem is inside the water cause short circuits. Vehicles and other locations in the door frame has rubber sealing strip, on the one hand is to ensure that the vehicle sound insulation, the other is to ensure the tightness of the vehicle.
Vehicles, especially older vehicles cable sealing areas need attention, you need to check and clean the door at the bottom drainage holes on the chassis and rubber seals, if clogged drainage holes or rubber ring security seal is not good, driving in the rain or through puddles when easily lead to compartments water, can cause severe short power cord compartment, the vehicle controller failures.
Therefore, Xiao Bian reminder, summer rainy season, the majority of owners should regularly check their car to do, early detection of the presence of the seal car-related issues in order to avoid self-inflicted damage.

New packaging cylinder seal testing equipment successfully developed

Program uses traditional manual inspection, workers record data to determine whether the product is qualified. In this process due to excessive labor participation, subjective emotional factors such as greater impact, resulting in detection of poor reliability, and increased risk of product delivery. With the increasing levels of industrial production, product testing on a higher sealing requirements, the use of automated test equipment instead of the previous artificial tightness testing to determine ways for users to comprehensively improve the rate of qualified products will help to get more orders.
The packaging cylinder (rocket launchers) Leak detection equipment, a differential pressure leak rate of detection of the workpiece, by a certain period of time known volume container seal sealed pressure variation inside the chamber, to measure the tightness of the DUT, test speed ≤ 60 秒/ piece (excluding labor to take up work time).
The high degree of automation equipment can automatically determine whether the product is qualified and leak rate value is given, the test criteria according to actual needs, set their own. Test data is automatically stored to the database, it can automatically generate reports to facilitate product quality management. Test full automation, without human intervention judgment, reliability, delivery risk is small.
In addition, the device can simultaneously detect duplex, with Ethernet interface, the test results can be uploaded to the LAN server to facilitate statistical analysis.
Dwell time set according to the measured product-related standards, different products dwell time can be adjusted. Diameter Φ80 ~ Φ100mm, height 890 ~ ​​930mm products, dwell time is 10 ~ 90s (setting step 1s).
Equipment with system calibration and leak rate pressure calibration functions, high precision. Leak rate test range is 1 × 10-4Pam3 / s ~ ∞, repeatability error ≤ 5% indicated value (to test standard leak leak rate values ​​prevail); leak rate test pressure, positive pressure: gauge 20 ~ 150kPa ( Set step 1kPa), pressure setting error ≤ 1kPa; vacuum: gauge -20 ~-60kPa (setting step 1kPa), pressure setting error ≤ 1kPa.
In addition to the tightness of the packaging tube for accurate testing, the device can cover sheet for rocket launchers blasting test, burst test pressure: gauge pressure 0.4MPa.
With cargo seals seal products in various industry applications, the constant increase in its testing requirements. To adapt to changes in the market, leading state apparatus with particular attention to the expansion of the device, the device after a few modifications, but also applies to ammunition, food, cosmetics, pharmaceuticals and other packaging barrel tightness testing.

Beware of cars damaged sealant aging

Rainwater infiltration sealant aging car even if the car is not water-soaked, after a rainstorm is also very likely a problem, the need for full testing and maintenance. Day after the downpour, the owner Mr. Luo take the car to go uncovered, a car door found in front of the driver's seat is water, foam pads have been wet, but the first officer position and the rear seats are very dry. Carefully check the windows, sunroof are closed properly, the car ran into the rain is how it? Inspection found that is due to the A-pillar near the rubber seal leaks caused by the failure of aging. Therefore, the owners usually have to check the vehicle sealing tape, such as the front windshield of the strip near the location of the security seal. Car wash when you can let the staff about using water jet edge sealing strip, check there is no water. If the seal problem, we recommend to buy the auto glass insurance vehicle, reported the insurance replacement; uninsured vehicle, you need to go to the beauty shop front windshield removed, with professional make up a good sealant stainless steel wire ties reloading. It is noteworthy that, to the way the check engine positions, such as whether there is water infiltration.

Regular inspection before the wind at the water tank interior modern vehicles are equipped with drainage holes, generally stagnant water inside the car mechanical and electrical systems severely affected by the situation is not much, but some of the longer period of time with the old car As the car sealant, etc. you need to pay special attention to the aging effect.

New technologies spherical diaphragm seal

With the petrochemical and coal chemical industry, high temperature, high pressure, medium and large-diameter high-risk, high flow heat exchangers such high-parameters in the device more and more applications, the traditional port sealing technology is facing new challenges. For example, the high temperature and pressure critical hydrogen exchanger tube box sealing device using a variety of structures, from the traditional long-necked flanges threaded locking ring seal structure to simplify its internal and external laps bolt seal structure, then Ω-ring seal structure, leakage occurred through the tube box case.
If the combination of these two advantages of the traditional structure, the diaphragm seal welded security seals and integration of the spherical diaphragm seal technology for high-parameter heat exchanger tube ends ports sealed container, it should obtain a simple structure, reliable sealing effect.
Conventional welding seal not often used in harsh conditions, removal of the flange joints, may be placed gaskets, simple structure, which does not belong to the structure of gasket pressure than more securely seal suitable for high temperature operation or temperature variation in a heat exchanger. On the other hand, the diaphragm seals in valves and pipe fittings in their long history, technology and reliable.
Diaphragm seal technology reduces spherical sealing surface, welded seal and reliable, and the middle part of the diaphragm has a certain elasticity, elastic deformation of the protective seal (truck seal)welding. Simple structure. Manufacture, installation cycle is short, simple maintenance and low total cost. In addition, generally used in austenitic stainless steel spherical diaphragm, on certain media can also play a role in the corrosion lining.
But at the same time, pointed out that the spherical diaphragm seal is a relatively new sealing technology structure, although foreign countries have good engineering applications, but Chinese domestic understanding and application of the technology has just started, it needs to further understanding and knowledge.

Seals technology innovation and development

Rubber seals are an important foundation element mechanical products, the manufacturing of high precision, as China's automobile manufacturing and the rapid growth of car ownership, seal products in the structure or materials are required on both high-precision technology and equipment support. In recent years, specializing in the production of seals in the part of enterprises to adapt to market positioning, timely adjustment of industrial structure and product mix, the rapid development and growth. Rapid increase in production output at the same time, in the production and testing equipment, experiments have also done a great investment.
◆ rubber seal material developments
Nitrile rubber seals used, hydrogenated nitrile, fluorine rubber, acrylic rubber, PTFE and other special rubber material formulation and processing technology research, improve material performance and utilization is still applicable to the focus. Applications of nanomaterials will enhance the mechanical properties of rubber material and special features. April 1 this year, the National Standardization Commission issued the first batch of four execution of nanomaterials GB, there is a rubber "ZnO" standard.
Special engineering elastomers replace low performance oil and rubber; bright surface of the rubber surface treatment; through nanotechnology rubber material modification and application of liquid rubber material, in recent years have made some progress. Especially some recent application of new materials for rubber cable sealing technology has played a great role in promoting.
The application of the padlock seals is relatively weak thermoplastic elastomer (TPE) having a vulcanized rubber physical properties and processability of the thermoplastic resin technology, molding process does not require vulcanization, which is the third generation of rubber. The main varieties of TPO, TPV, TPU has been widely used in the world: TPV applications in the automotive average annual growth of 15%, is generally EPDN and PP full crosslinking compound, which combines the high tensile strength, oil heat, etc. performance, long resistant to 150 ℃ hot oil working conditions, can be used to replace the production of automotive EPDM seals and other products; TPO is currently using more EPDM with polyethylene component composition, production process is mechanical mixing and dynamic vulcanization. Dynamic vulcanization production of the TPO. Rubber component is as high as 60 to 70%, abrasion resistance, ozone resistance, high tear strength, compression deformation is small, the overall performance is better than EPDM vulcanized rubber.
United States, Western Europe and Asia continue to build TPO production unit; TPU plastic and has excellent processing properties and physical properties of rubber, and its wear resistance, low temperature resistance, excellent radiation performance in the automotive, aerospace, medical and health , household items, military supplies and other industrial applications have great progress, TPU can be widely used in automotive shock absorber, bushings, bearings, bushings, airbags and other components.

Polyurethane seals materials development and application of

High-temperature polyurethane material
Modern thermoplastic polyurethane (TPU) security seals operating temperature from -40 ℃ ~ +120 ℃, and strong chemical medium can also be adapted. While also maintaining a high capacity and good wear resistance to extrusion and other basic properties. Even in the case without lubrication, the piston rod seals can be under a pressure of 10MPa 0.05m / s speed reciprocating motion. Through the ISO standard cylinder piston seals long-term tests showed that the life of the seal polyurethane material is the same shape and size of nitrile rubber seal 5 to 6 times.
Polyurethane seal material as in the 20th century in the early 1980s to get a breakthrough. At that time, including a number of companies, including Parker manufacturers develop more hydrolysis resistant polyurethane material, these new polyurethane seal at high pressure and which maintain high flexibility +110 ℃, to achieve a better sealing performance, as well than the original The polyurethane (only resistant to high temperature +80 ℃) longer working life. This achievement opens the door to mobile hydraulic applications, whereas before designers in the industry do not trust very original polyurethane material seals. 1989, P5008 materials obtained using an approved Caterpillar plants worldwide, this recognition marks the Parker trailer seals Polyurethane materials application in earthmoving equipment to achieve a breakthrough. Thermoplastic polyurethane (TPU) Seal System application in the excavator soon largely replaced by 5 to 7 V-ring rubber cloth portfolio structure. Ten years ago this success, making further expanded its investment in the development of new polyurethane material. The new "custom-made" thermoplastic polyurethane material varieties, shapes and seals more more economical production expanded range of potential applications.

Ceramics factory commonly used hydraulic seals

Hydraulics with small size, light weight, small inertia, smooth motion, can transmit large forces and other characteristics, but also has convenient control and easy to implement process automation, etc., so the hydraulics have been widely used in national defense and agricultural production sectors. Such as ceramics factory widely used hydraulic piston pumps, hydraulic presses and hydraulic carts machines.

Especially the reform and opening up 20 years, with hydraulic drive, electronic and digital control technology development, China's ceramic tiles manufacturers generally adopt the world's most advanced automatic hydraulic press production of ceramic tiles, in order to meet domestic and foreign markets. At the same time, China's household ceramics and sanitary ceramics industry has also been a vigorous development, such as household ceramics, dish type isostatic molding production technology and production equipment and low-voltage fast drainage, medium-pressure and high-pressure injection grouting pulp molding production of sanitary ceramics technology and promote the use of production equipment have made gratifying achievements. However, these hydraulic machinery hydraulic drives fatal weakness is the hydraulic oil leaks, it not only affects the hydraulic drive system performance and productivity, but also pollute the environment and waste production resources. Practical experience has shown that production, solve ceramics factory machinery hydraulics hydraulic hydraulic oil leak is the choice of the most effective ways to rail car seals sealing performance. Even though most ceramic manufacturers understand hydraulics particular hydraulic cylinder seals used some basic common sense, but its lack of systematic and comprehensive understanding, so in practice, production, hydraulic cylinder seals commonly used quality is often ignored by people , storage improper storage, assembly and disassembly savage, resulting in the cylinder cargo seals commonly aging, injury, or a greater plastic deformation, and even loss of the seal, resulting in leakage of hydraulic oil. So learn ceramics factory used hydraulic seal performance, material, structure, mechanism and influencing ceramics factory sealed hydraulic seals commonly used sealing performance factors, through the selection of suitable materials and appropriate structure in the form of hydraulic seals, and take appropriate protective measures can be used to maximize the ceramic factory hydraulic seal sealing performance and economic efficiency of enterprises.

The role and significance of the seal

The role and significance of the seal Abstract: hydraulic systems and system seals to prevent leakage of the working medium outside intrusion from dirt and dust sealing element sealing leakage caused by the working medium machine environment pollution caused by waste machinery accidents caused by malfunctioning equipment volumetric efficiency of the hydraulic system of a sharp decline working pressure not less than required to work into the system caused by tiny dust particles 2002: machine tools, the WTO is a challenge but also opportunities for experts pointed out that China's CNC machine tools to increase research and development efforts to accelerate the development of universal CNC machine tool manufacturing services Rambling Chinese competition in China milling machines and machining centers market situation and outlook abroad lathe level of technology and development direction of the world production of machining centers, needs and developments at home and abroad the world development trend of CNC machine tools trends CNC machining technology and the development of the hydraulic system and their system, the marker cable ties sealing means for preventing leakage of working fluid and the intrusion of dust and foreign matter outside. Wherein the seal element, namely seals. Leakage will result in the waste of the working medium, pollution, machines and the environment, and even cause malfunctioning machinery and equipment, personal accident. Endoleaks volumetric efficiency of the hydraulic system will cause a sharp decline, reach the desired working pressure, can not even work. Intrusion systems tiny dust particles can cause or exacerbate the wear of hydraulic components, and further lead to leakage.

Therefore, Security seals and sealing device is a hydraulic device is an important component. It's the reliability and service life of the hydraulic system is a measure of an important indicator of good or bad. In addition to the gap seals, are the use of seals, so that two adjacent coupling gap between the surface of the liquid to be sealed controlled through the following minimum clearance. In-contact seal is divided into self-sealing compression seals and self-styled self-tight seal (ie lip seal) two kinds.

Summary seal types and standards

About professional products: Refers to the mechanical seal used in professional products to meet the hydraulic system a particular purpose, such as construction machinery on the buffer ring, high packing seal ring; altitude and safe operation of the special mechanical seals; temperature mechanical high-temperature and low-temperature mechanical seals on cold seal; pressure rotary machine, high pressure seals, etc., these products are not included in this catalog.
About general machinery: general machinery is referred to here in the general pressure, speed, temperature rating and other occasions using hydraulic machinery and equipment, its system security, and operational characteristics such tasks is not very special requirements, so the use of seal products will not make excessive performance requirements, such as general hydraulic machines, general machine tools, forklifts, plastic machines and light industrial machinery.
About the specialized machinery: specialized machinery is referred to here in particular pressure, speed, temperature class and special occasions the professional application of hydraulic machinery and equipment, its system security, work tasks, operating characteristics, environmental conditions, etc. have a certain expertise requirements, so that it can effectively accomplish specific tasks assigned, so the use of this type of mechanical security seals products have a special performance requirements of certain aspects (particularly if the reliability of pressure resistance, speed, performance, temperature performance, durability performance and safety, etc.), this type of machinery such as aerial work machinery, cranes, mining machinery, steel, machinery, port machinery and some maintenance equipment.
About maintenance products: Is the mechanical equipment being used when there is hydraulic system failure, urgent need to replace the hydraulic seals, hydraulic equipment needed or when the system transformation, re-select the proper application of seals. The supply of these products feature requires timely, accurate, effective and reliable.
About ancillary products: processing in the factory production of hydraulic system and hydraulic cylinders, you need to use the technical, performance, quality, standards, cost, delivery period, etc. to demonstrate selected so that the hydraulic equipment to meet the advanced technology, reliable performance, cost reasonable, timely delivery, after-sales service and easy. This is a very rigorous system works, over the years our company has been in line with industrial enterprises one after another sealing systems supporting business.
About Machine Repair Kit: the hydraulic system of the mechanical equipment of a component or unit body for maintenance, the need to replace the seal assembly parts, so that the mechanical Security seals replacement system has been repaired its performance back to its normal state, such unit supply The seal assembly is called machine repair kits. Machine repairs within the package seals must fully meet the original parts of the technical and performance requirements in order to make the repaired machine into normal use.

Hydraulic seal installation and removal

Installation and removal of the ceramic factory used hydraulic seals, in order to prevent the hydraulic plastic strap seal is threaded, undercut such an acute angle to scratch the sealing performance, we must adopt the following measures:
A) shall cylinder, piston, piston rod and the guide sleeve ends and other uses 15 ~ 30 ° angle smooth introduction.
2) When the hydraulic seals must pass male or retraction bad, they should put in their respective positions on the special sleeve, you can also make the outer diameter of the external thread or undercut the hydraulic diameter less than the inner diameter of the seal.
3) When the hydraulic seal to the internal thread or radial through holes, should the inner diameter or radial threaded hole is larger than the diameter of the outer diameter of hydraulic seals.
4) To reduce the hydraulic meter seals installation and removal of resistance, hydraulic seals should be subject to the appropriate location on the coated lithium soap grease or hydraulic working oil, hydraulic seals and try to avoid excessive stretching, in order to avoid the plastic deformation affecting the hydraulic seal of the sealing performance.

No-contact gas lubricated mechanical seals is how to work it

In operation, the gas-lubricated mechanical seal without contact between the sliding surfaces of the two should be a layer of only a few voids Xie meter, in order to produce voids, non-contact type mechanical seal of the two sliding surfaces disengage one another . To achieve this, a three-dimensional ring groove made to ensure that the air is static and dynamic play. Seal in the stuffing box pressure difference generated at the aerostatic effect, while the rotation of the aerodynamic effect. The resulting force balance lift and closed, thereby forming a width of 1 to 5 Xie seal gap.
Applied in the mixer without touching gas lubricated mechanical seals
The gas in the mixer using the non-contact type mechanical truck security seals for the user has three major advantages: 1, no liquid leakage; 2, the product quality is not affected; 3, on the reaction with little or no effect;
Non-contact type mechanical seal also has some other advantages. Include: 1, the operation clean (GMP); 2, low friction loss; 3, the noise does not occur; 4, mechanical wear little or no wear. If the seal system used in the mixer for the above requirements, then such seal member is operable.
Pressure purposes, without contacting mechanical seals are usually used in vacuum conditions, up to 6bar.
Mechanical seal according to the user part of the liquid lubricated seal for many years experience in the use of liquid seal is not used in the past for each of the products are suitable for gas seals. The main factors to consider for sealing products with high sensitivity (eg, sealing surface is touched). To counteract this effect, many types of research and the use of additional components, such as the patented flush mounting flange. When not contact mechanical seal sealing surface when the automatic alignment feature degradation, self-converted to gas consumption, the sealing surface is blown or is rinse. The mounting flange can be used for washing steel container, especially for the enamel container (plastic container). Apart from the gas seal applications beyond the experience gained in the storage and use has also made a series of new insights. When the seal member to achieve its first time of change, and start using the ship between the seal member, may be after many years. Same time, various factors can influence the characteristics of the gas mechanical security seals member. In the assembly accidentally add too much grease or oil - grease or oil into or penetrate into the sealing gap. Then, in use, thereby causing uneven gap, mechanical seal damage. According to experience mechanical seal at its beginning before use should be checked.

Commonly used self-sealing compression hydraulic seals

Commonly used self-sealing compression hydraulic PTFE seals mainly O-ring, round and square ring seals, etc., which has a simple structure, easy to manufacture, low cost, etc., so they are hydraulic drive widely used in dynamic sealing element and static sealing.
Hydraulic black cable ties mounted in the sealing groove generally produce 10-25% of the radial compression deformation, and the sealing surface to produce a higher initial contact stress, thereby preventing leakage of the liquid without pressure.
Hydraulic cylinders work, the pressure fluid squeeze self-sealing compression hydraulic seals, so that further deformation, and the sealing surface with a greater pressure on the liquid pressure, the pressure should be strictly. The additional increased and increased contact stress and stress together with the initial contact pressure to prevent leakage of the liquid. However, when the working pressure is greater than 10Mpa, in order to avoid self-sealing synthetic rubber-type hydraulic Security seals compression portion of the sealing gap is extruded into reciprocating motion in the cylinder is cut off and cause leakage, to puncture the synthetic rubber-type pressure tight seal hydraulic pressure side of each setting a synthetic resin retainer, such as nylon ring, ring and PTFE POM ring.

Application of organic silicon products

Silicone products have good resistance to high and low temperature performance, can usually be at 180 ℃ under high temperature long-term work. Silicone rubber at 250 ℃ can work a long time, instantaneous ability over 1000 degrees Celsius. Silicone Materials Low temperature performance is good, generally -55 ℃ can still work. Some of the silicone rubber is still elastic at -110 ℃. Silicone material has good electrical insulation properties, dielectric properties do not vary with temperature and radical change; permittivity increases without increasing frequency value; and arc resistance, corona resistance, leakage; resistant to ozone, radiation, tamper proof padlocks weathering , flame retardant, so extremely versatile. Below are several categories of silicone products were briefly a part of the main purposes:
1 silane coupling agent is a silane coupling agent class of low molecular weight compounds, the silicon atoms are connected to one end of a variety of hydrolysable chlorine or an alkoxy group, the hydrolysis can be connected with inorganic; other end with a variety of the role of organic phase functional groups such as amino group, a vinyl group, a mercapto group, and the silane coupling agent, organic and inorganic substances can bridged together. Silane coupling agents are commonly used in hundreds of species. Such as glass, steel, glass fibers to be used is necessary to use a vinyl-containing coupling agent to improve the wet strength. The current popularity of "green" tires on the extensive use of thiol-containing silane coupling agent; vinyl trialkoxysilane with crosslinked polyethylene, its working temperature can be high than ordinary polyethylene and polyvinyl chloride, suitable hot water system pipes, cable sheathing.
(2) silicone oil or a silicone oil containing a single type of low molecular weight organic polysiloxane groups,wire seal can be made into a variety of different viscosity. Low surface tension of silicone oil, a large contact angle with water, water repellent material of high quality. Silicone oil viscosity-temperature coefficient of variation is small, does not solidify at low temperatures and is resistant to both high temperature and low temperature aerospace gyroscope oil, antifreeze and heat-resistant lubricating oil, hydraulic oil, instrument oil, base oil, as well as steam low pressure high vacuum diffusion pump oil. Silicone oil or a modified formulation in cosmetic applications has grown rapidly in recent years. Silicone oil paint on the skin not greasy feeling smooth, comfortable, can be made into various skin creams and so on.

How to choose the seals

Pressure
High and low pressure, the pressure variation cycle length, the seal is broken (such as extrusion) has a great influence. The higher the pressure, the sealing member other factors greater impact on the performance, such as temperature, speed, the bolt security seals material, the piston and the cylinder gap between the piston and the gap between the cylinder head.
Temperature
As a seal material to the maximum temperature and the minimum temperature is difficult to describe, because it is the result of the combined effects of a number of factors. The piston and rod temperature is different, selected to distinguish them.
Friction
Fixed Length plastic seal and friction surface depends on many factors: the surface roughness, surface characteristics, pressure, media, temperature, material of the seal, the seal type and velocity.
Surface treatment
Experience has shown that the surface of the cylinder piston and piston rod seal life characteristics on has a very big impact. Surface roughness of the surface characteristics used to define the value of RA, RA is a surface shape of the arithmetic mean of the absolute deviation from the center line. However, these values ​​can not be fully expressed on the surface condition of the seal, because even in the same roughness, different characteristics of the surface shape of the seal may lead to different levels of wear of the sealing member.
Analysis of the above points, choose a more scientific seal selection, the entire hydraulic system is of crucial importance to play a role.

Commonly used self-sealing compression hydraulic seals

Commonly used self-sealing compression hydraulic PTFE seals mainly O-ring, round and square ring seals, etc., which has a simple structure, easy to manufacture, low cost, etc., so they are hydraulic drive widely used in dynamic sealing element and static sealing.
Hydraulic seals mounted in the sealing groove generally produce 10-25% of the radial compression deformation, and the sealing surface to produce a higher initial contact stress, thereby preventing leakage of the liquid without pressure.
Hydraulic cylinders work, the pressure fluid squeeze self-sealing compression hydraulic seals, so that further deformation, and the sealing surface with a greater pressure on the liquid pressure, the pressure should be strictly. The additional increased and increased contact stress and stress together with the initial contact pressure to prevent leakage of the liquid. However, when the working pressure is greater than 10Mpa, in order to avoid self-sealing cargo seals synthetic rubber-type hydraulic seal compression portion of the sealing gap is extruded into reciprocating motion in the cylinder is cut off and cause leakage, to puncture the synthetic rubber-type pressure tight security seals seal hydraulic pressure side of each setting a synthetic resin retainer, such as nylon ring, ring and PTFE POM ring.

Domestic and foreign enterprises launched a new sealing material

1, perfluorinated rubber FFKM
High temperature (250 ℃ ~ 320 ℃), gas and a strong resistance to chemical corrosion, good elasticity, low compression set, good elasticity, etc., to adapt to some very harsh working conditions. In the chemical, food, printing, semiconductor and other industrial applications. Parker, Evco other companies launched.
2, fluorine plastic coated rubber products
FEP (fluorinated propylene) and PFA (perfluorinated compounds) such as fluorine plastic varieties, coated rubber O-rings and rubber gaskets (eg plate heat sealing), medium resistance to improve rubber products (solvents, acids, alkalis ), Shanghai Yi Gang, EVCO, Fluorten other companies launched.
3, the unique polyurethane material
PU 92 AU 21100 good lubricity, anti-ultra-low temperature performance up to 20K (-253 ℃) resistance to ultra-low temperature conditions apply. Simrit exclusive launch.
4, polytetrafluoroethylene (PTFE) composite and modification
In order to overcome the cold flow of PTFE, defects and poor thermal conductivity, reducing wear products, the use of PTFE as a matrix and carbon fiber, polyimide (PI), polyether ether ketone (PEEK), polyphenylene sulfide (PPS) and other materials complex, development of non-oil lubricated tamper seals (piston rings, guide ring, packing ring), in the high-pressure oil-lubricated compressor widely used. Wide research and development of such Security seals seals, used in many famous compressors.
EPTFE applications, expanded polytetrafluoroethylene stretched, puffed have formed after the tough and porous, highly fibrosis new material, not only to maintain its unique chemical stability of PTFE , low friction coefficient, a broad operating temperature, and it is more so that the internal structure of micro-fibrosis products with unbelievable tenacity.

Non-contact gas lubricated mechanical seals use

When discussing the mechanical seal, the most important thing is to figure out the differences between various sealing systems. Mechanical seals are three basic types: fluid lubricated mechanical seals, gas lubricated mechanical seals and touch off style or called non-contact gas lubricated mechanical seals.
These types of mechanical seals difference is in the fluid-lubricated sliding surface of the seal between the fluids. These seals are usually applied mixed friction purpose mixer. For dry running seals, two sliding surfaces in direct contact with each other. On the other hand, the non-contact gas-lubricated mechanical seals, in the operation of the sliding surface is not in direct contact. There are 1 ~ 5μm wide gap separating the surface, which is why this is often referred to as the seal seals from seal causes. When referred to the gas damping double seals should have this distinction. Here we will discuss only non-contact gas lubricated mechanical gas plastic truck seals.
No-contact gas lubricated mechanical seals is how to work it?
In operation, the gas-lubricated mechanical security seals without contact between the sliding surfaces of the two should be a layer of only a few voids Xie meter, in order to produce voids, non-contact type mechanical seal of the two sliding surfaces disengage one another . To achieve this, a three-dimensional ring groove made to ensure that the air is static and dynamic play. Seal in the stuffing box pressure difference generated at the aerostatic effect, while the aerodynamic effects generated by the rotation. The resulting force balance lift and closed, thereby forming a width of 1 to 5 Xie seal gap.

Common Seal Material Description

Depending on the application may be different in different types of security seals used in combination to accommodate different sealing conditions. Its commonly used materials can be divided into two categories, namely rubber and resins. A rubber sealing material used nitrile rubber, polyurethane rubber, fluorine rubber, silicone rubber, commonly used resin sealing material PTFE, phenolic resin, polyamide resin.
First, the rubber is a high elasticity of the organic molecular compounds, the main component of natural or synthetic caoutchouc. Raw rubber after vulcanization process and after adding various ingredients, so that the rubber can be made with our performance requirements. The rubber sealing systems are mostly used nitrile rubber, polyurethane rubber, silicone rubber, fluorine rubber.
1, the nitrile rubber is a copolymer of acrylonitrile butanediyl the body, it has good oil resistance, abrasion resistance and aging resistance around the song, so it is the most commonly used synthetic rubber.
2, polyurethane is a polyester or polyether with diisocyanate polymerization of the compound, it is high wear resistance, oil resistance, aging resistance, ozone resistance, in addition, is also very good air tightness.
3, the use of silicone rubber wide temperature range, anti-aging and resistance to radiation resistance.
4, fluorine rubber is a copolymer made by the fluorine-containing monomer organic elastomers, high temperature up to 300 º C, acid and alkali, abrasion, sunlight resistance, flame resistance, excellent air tightness is the overall performance of special synthetic rubber. Viton deficiency is poor cold tolerance, resistance to poor processability, low elasticity and expensive. Usually used to make the rubber O-rings, oil seals, rotary lip plastic seal, reciprocating seals, etc., the seal industry, one of the most commonly used materials.

The role of valve seals

You can prevent the oil into the intake and exhaust pipes, resulting in loss of engine oil, gasoline and air mixture to prevent gases and emissions leakage, prevent engine oil into the engine combustion chamber. Engine valve valve padlock seals is one of the important parts group, at a high temperature in contact with gasoline and oil. Therefore requires the use of heat resistance and oil resistance of the material, generally made of rubber is a fluorine.
Valve seal structure
Installation and replacement of valve seals
(A) the valve stem oil seal removal steps:
① Remove the camshaft and hydraulic lifters, and kept face down, the operation should note tappets are not interchangeable. Remove the spark plug with a spark plug wrench 3122B, adjusted to the corresponding cylinder piston top dead center, the pressure hose VW653 / 3 spark plug screwed into the threaded hole.
② the spring compression tool with bolts attached to the cylinder head 3362. The associated valve adjusted to the correct position, and then the pressure hose to the air compressor (air pressure of at least 600KPA). Threaded mandrel and thrust pieces down the pressure valve spring, remove the spring.
③ can tap Remove the air lock valve spring retainer block. Tools pull valve stem seals 3364.
(2) the installation of the valve stem seals.
The plastic package to the valve stem to prevent damage to the new valve stem seals. Kouqing coated in oil plastic strap seal lip. The 3365 oil on package to the tool, and then slowly push the valve conduits. Special note: Install the intake and exhaust in front of the valve stem must be coated with a layer of oil.

Special installation is required gasket

1, the installation and the sudden planar spiral wound gasket sealing flange match, should be taken to ensure the security seals concentric with the pipe, commonly used to strengthen the outer ring and the inner circumferential surface contacts the bolt to locate, not eccentrically mounted. Tongue and groove sealing surface mounting flange of the basic type spiral wound gasket, attention should be consistent with the groove wall to keep the gap.
2, the installation of the metal-coated gasket narrow width, the thickness of the plate should be placed in a lateral pads, and then pressing the flange, the coated metal gasket to prevent compression of the filler, the interfaces of the metal shell (or take the mouth) expansion opened, damaged metal jacketed gaskets.
3, when the flange temperature higher than 200 ℃, the flange and gasket sealing surface should be coated with sealant between to prevent high temperature gasket and flange sealing surface sintering, to increased maintenance and replacement gasket trouble.
4, the sealing surface is not flat, the surface can be coated with the sealing gasket sealant before installation. Sealants generally manganese dioxide, lead, graphite powder and survived after linseed oil (drying) components. According to the cable sealing medium, temperature and pressure conditions choose the appropriate media type and brand of liquid sealant.
5, for the installation octagonal metal ring gasket, when the metal ring gasket and flange seal groove machining is not ideal, it can be achieved by coordination study snug fit. For large diameter metal ring gasket, with research more difficult, in order to fill tiny uneven metal surface, use sealant.