Pump mechanical seal maintenance, overhaul should pay attention to several issues

1 , lubrication
The mechanical seal faces should be properly lubricated , thus reducing wear and prolonging life , some lubricant friction heat can also be taken away . Lubricants generally assumed by the media itself ,wire seal thus sealing face ( ring, stationary ring ) see spring pressure should not be too large.
2 , flush cooling
Pump mechanical seal end face of the work so that the heat generated should be promptly passed out, otherwise it will vaporize liquid film between the end faces formed by dry friction, flush cooling measures must be considered .
Generally flush with internal coolant sealing medium , may also have an external water supply cooling water. Should be used in mechanical seal flushing coolant absolute guarantee of supply and flush the coolant flow, if necessary cleaned regularly.
3, the old seal update
In contrast with the new mechanical seal better than the old , but the new mechanical seal quality or choice of material is not the time , with the larger size of the error will affect the sealing effect ; sexual penetration in the polymerization medium, the stationary ring without excessive wear, or not to replace as well. Because static ring stationary ring seat for a long time in a quiescent state , the polymer and impurities deposited as a whole, played a good seal.
4 , the seal overhaul
Once the mechanical seal leakage will be eager to overhaul , in fact , sometimes sealed and not damaged , simply adjust the working conditions or the seals can be adjusted to eliminate leakage. padlock seal This way to avoid waste and to verify their ability to judge the fault has accumulated experience in maintenance to improve the quality of maintenance .

Flat metal seal butterfly valve pneumatic Characteristics

In recent years, the use of butterfly of modern industrial development, extended from the low-pressure water to a temperature higher than 538 ℃, -184 ℃ low to medium pressure from low to high , widely used in air separation , chemical industry, metallurgy, sewage treatment and other fields. And caliber growing, higher performance requirements , require a longer service life .
Currently, the majority of domestic and foreign production of rubber sealing butterfly valve and plastic seals, easy to wear and aging , reach equipment for continuous operation cycles. In air separation , for example, today in cryogenic separation principle -based air separation plant , which processes are using molecular sieve pre-purification processes, working pressure of 0.5 ~ 0.9mpa, medium temperature range of 10 ~ 200 ℃, its switching valve used temperature, caliber , frequent switching valve rubber seals easy to wear and aging, but also more difficult to replace .
For these situations , developed a metal rod by force plane sealing pneumatic valve series. The new valve has been the national utility model patent ( patent number : zl97224037.3).
1, the metal flat sealing pneumatic valve characteristics
( 1 ) The lever hoist structure, so that the relative sliding between the sealing small decreases relative wear .
( 2 ) using the rod actuator force increasing mechanism . The butterfly valve is in the closed state agencies ,security ties the drive unit can output maximum torque , and has a self-locking performance , safe and reliable .
( 3 ) use of flat metal seal structure, with strong corrosion resistance and wear resistance, suitable for high temperature environments , long service life .
( 4 ) key components has been optimized so that the total of the valve opening and closing times can reach 1 × 106 times.
( 5 ) of the valve control system uses non-contact magnetic reed switch , from environmental conditions, and the signal sensitivity , high accuracy, can achieve remote control , pneumatic control and automatic control , and ancillary equipment can also be achieved without person operation.

Water pump mechanical seal Precautions

Water pump mechanical seal device , if used improperly installed metal ring seals can be easily damaged ,tamper evident tape causing the pump does not absorb water , the water shortage and other faults.
Therefore, use should note the following:
1, using the former must add enough water to prevent dry friction .
2 , If the pump is leaking from the pulley side , should immediately identify the cause and add oil.
3 , try not to smoke silt , weeds and more water .
4 , the impeller thin wall easily broken , if demolition should gently pry the impeller .
5 , check the rubber quality, installation is best dip .
6 , rotating bearing body , pull tight seal checking static ring and shaft with the gap , should be uniform . Such as static deflection ring installation should be corrected immediately.
Ready to clear the overflow hole , to prevent water from entering the bearing , diluted lubricant .

Diesel fuel injection pump and the reasons for exclusion Mifengbuyan

Diesel engine fuel injection pump and the oil is turned on, to form a sealed circuit , when the original body of the air , the engine should stop working for no oiling .
At this time, machine hand should first check the stock of diesel fuel in the tank , if exhausted , into the pharynx whether to leave the oil pipeline ; second is to check whether the fuel tank outlet is blocked , resulting in the formation of vacuum circuit can not supply , then the fuel injection pump bleed screw loose, hand pumps pump oil, if a large number of bubbles or oil foam appears and oil do not feel carefree ,cargo seals indicating low pressure oil are blocked , then check the coarse and fine diesel filter clear whether the blockage , tubing for cracks , touch deflated ; whether the tubing joints forget to install the gasket or gasket is damaged, causing a leak or the air intake .
When the hand pump oil pump , oil feels very smooth, but there is no pressure, which was mainly due to fuel pump relief valve in the oil return on spring break or fatigue deformation, wear or dirt ball paving and Mifengbuyan so low oil pressure oil supply shortage caused by low fuel pump . Check the return oil pressure relief valve sealing effect , hand blocked inlet mouth blowing , blowing does not move as normal, otherwise Mifengbuyan , hand pumps pump oil, the handle should feel a stretch tic pressure very easy to handle when opening or automatic back .
For the old-fashioned hand pump should also check the fuel pump inlet pipe to the fuel tank between the oil is blocked, if the majority is due to clogging pump inlet strainer below clogged by dirt or gasket damaged due. Hand pump oil pump shaft the handle when you feel no suction, when the handle is depressed , feeling great resistance , mainly between pump the oil to the oil pump clogged . Mostly due to fuel pump inlet screw with anti-loaded pressure relief valve , fuel pump in the non-return valve installed backwards or wear off very , hand pump aging damage rubber container seals and other reasons .
Such as fuel injector return pipe has a lot of bubbles appear , which was mainly due to a cylinder injector nozzle stuck in the open position , he went to the high pressure gas cylinder injection pump body . The oil filter return pipe connected at one end removed, blocked oil return port filter , bubbles disappear , indicating a fault in the fuel injectors, and then find which cylinder injector nozzle is stuck, be ruled out.

The valve sealing performance is very important

Sealing surface material and the processing status of the valve sealing performance of the sealing surface of the valve material and processing conditions have a significant impact leakage . As the remaining gap between the seal faces depends on the sealing surface micro-roughness , so that , if the use of steel materials, seals, resulting in sealing of the same , there must be greater than the pressure , the value must exceed brass system value than the pressure seal . The sealing surface of the processing state , such as a peak distortion , high security bolt seals and sealing the gap size changes and other phenomena occur on the metal surface , it is clear that the performance of the surface properties of the base material have significant difference . Induced changes in the machining surface can affect the thickness of 50μm. Grinding the base metal is not exposed . Work is different from the metal surface tissue matrix organization . Geometry and material properties and microstructure geometry compared to little effect . Differences in the performance of metal , usually less than other factors . Sealing surface when working under low pressure conditions , the situation is more prominent. When the pressure ratio is higher than 40MPa , the surface roughness of the sealing performance is reduced , and the impact of the material is increased.
Hydrophilic surface properties of the valve sealing surface of the leak amount of hydrophilic properties due to capillary effect. When the sealing surface as long as a thin film, the need to increase the pressure of the water through the gap . As the metal surface with good hydrophilicity, kerosene can easily penetrate the gap casting and sealing connection . So, in some of the most critical situations , is the use of kerosene for the hydraulic tightness test . Filling the cavities of kerosene tightness test method , equivalent to approximately 0.3 ~ 0.4MPa water pressure tightness test under pressure .
Properties of the medium on the valve sealing performance of the liquid medium is substantially on the leakage of the viscosity determined by the sealing valve in the same , the various conditions are the same , the viscosity of the medium viscosity smaller than the much smaller leakage medium . Gases and liquids compared to the difference more obvious ( except for saturated steam , saturated steam is easy to ensure the sealing surface ) .
The closing member of the rigidity and structural features of the valve closure member sealing performance and structure of the rigidity is due to the elasticity of the part . The closed valve closure member is not absolutely rigid , but has a certain flexibility in the pressure of the medium , the size is changing, which force causes the sealing surface interactions. To compensate for these changes on the sealing performance of the closure member , cable ties the sealing surface preferably has a smaller rigidity of the elastic deformation is as large as possible . Hope valve manufacturer importance of factors affecting the performance of the valve seal , the valve sealing performance caused by leakage minimized to prevent leakage and leakage within the valve .
The presence of the sealing film of the valve sealing performance of the sealing film exists between the sealing surface has a significant effect on its sealing performance . When the sealing film on the surface , the destruction of the contact surfaces hydrophilic , so that a larger pressure difference is required to make the medium passes through the pores . In addition , dense sealing film on the surface of the channel to plug the media travel , improve the connection sealing. In the use of film sealing should pay attention: When the work process film is reduced, should be able to recover the oil film thickness. Oils used in the valve being not soluble in the media , nor should evaporate , hardening or other chemical changes .

Structural characteristics of the mechanical seal

From the structural characteristics of view , the mechanical seal type varied, but by component speaking, it mainly has the following four basic elements:
1 , the buffer compensation unit
A spring element which consists of the main buffer compensation mechanism , which is to maintain the important mechanical truck sealseal normal conditions .
2, the sealing unit
I.e. the rings of the ring and stationary seal faces , which is the core of the mechanical seal .
3 , the auxiliary sealing unit
The ring seal and the static ring seals and other components, it is to solve than the sealing face , the site of leakage possible auxiliary sealing means is a mechanical seal elements indispensable .
Mechanical seal is a fluid sealing technology promising a plastic seals sealed form , has now reached working pressure of 40MPa, face mean sliding velocity 150m / s, pv value of 200MPa • m / s level. Can meet the requirements of most production process conditions .
4 , the drive unit
By the sleeve , button or pin consisting of a fixed transmission mechanism , it is to achieve the ring rotates with the shaft a reliable guarantee , but also a prerequisite to achieve dynamic seal .

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 aerodynamic effects generated by the rotation . 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 seal 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 high security bolt seals 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 pull tight seals member , may be after many years. Same time, various factors can influence the characteristics of the gas seal 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.

Hydraulic equipment damage caused by the impact of seals

Mechanical processing industry, hydraulic transmission is widely used, such as lathes and other types of semi-automatic hydraulic transmission . These machines during use , such as the impact of frequent , reptiles and other faults , diagnostic repair, often in the hydraulic control components ( such as various types of pumps, valves ) can not find the cause of the malfunction , resulting in maintenance trouble. The final such failure or normally found on the actuator causes the cylinder piston sealing element due to severe wear . Such phenomena especially "O" ring seal see more .
Example 1: a CE7120 hydraulic copying lathe, turret profiling occurs in the work cited by the sword turn longitudinal feed line cutting die cutter , resulting knife fight , scrap living phenomenon frequently, the machine does not work.
Inspection and Maintenance : Check no fault of the hydraulic control components , maintenance work temporarily into the blind spot. Overhauling vertical turret tank, found that the piston seal "O" ring seal has been polished cylindrical , cylindrical piston also found substandard size requirements ( genus machine tool manufacturing reasons ) , the diameter direction is less than standard size 0.8mm, piston and cylinder body clearance large, causing vertical cylinder two chambers communicate channeling oil . Maintenance, and replacement of the piston passing "O" -ring after the die cutter machine troubleshooting. Analysis of the reasons cited in the profiling tool holder in place of the instantaneous line of the sword , the whole holder to receive a momentum F ', the force is decomposed F'1 a horizontal force acting on the cylinder piston rod longitudinal direction , at the same time , the solenoid valve 34E1-25B work turned vertical cylinder rod chamber pressure oil chamber connected rodless return oil control valve , the piston rod chamber by the force F by the two partially completed , one for F'1, the other is F1 = A1P1, where A1 is rodless chamber force area , then F = F'1 + F1. Under normal circumstances , the piston under the action of the force F rod chamber began to move , as incompressible hydraulic oil , hydraulic oil pressure rodless abrupt increase cavity to form a back pressure piston , the piston control valve according to the force balance it is set to go steady speed knife . The moment due % F'1 role in longitudinal cylinder chamber pressure P2 will be greater than P1. In practice, the two-chamber cylinder gap channeling due to the P2> P1 moments, hydraulic fluid from the high pressure zone with rod chamber rod chamber to the low pressure area flow trends , liquidity , once produced , P2 reduced , P1 rises , F1 increase large , unbalanced force piston , the piston driven turret quickly moves to the rod chamber . And moments later, the end result of profiling tool slide downward acting on the piston in the cylinder longitudinal horizontal thrust F'1 disappear on their own fast-moving piston end , take the knife stabilized turret , plastic seal red knife phenomenon ends.
Example 2: a CB3463-1 semi-automatic programmable hexagon turret lathes, during use , the emergence of the turret feed rate can not adjust the failure phenomenon , globe valve 2 is closed there is still crawling, pediment , and has been to bottom of the tank to stop the machine does not work properly .
Inspection and Maintenance : Inspect all hydraulic control components , especially the governor components have not found any problems. Replace some of the control valve , the failure persists . After dismantling the cylinder after the discovery piston "O" ring seal badly worn , so that the two chambers of hydraulic oil cylinder channeling each year. Analysis of the reasons , because "O" -ring wear, cylinder rod chamber and the rod chamber gap increases interoperability, when closing valve control valve 3 or 2:00 , it means cutting off the cylinder rod chamber oil return road. Theoretically , the pressure oil into the cylinder rod chamber when the piston is formed without a force F , the piston rod chamber to move the trend, as the cylinder rod chamber back to the oil off the rapid formation of the oil cavity back pressure , so that the force balance across the piston stationary ,truck seal F a = F no time , no fluid pressure chamber due to the piston force different size and different, that is, P a > P no . In practice, a gap is formed due to the two chambers communicate with each cylinder , the cylinder chamber with pressure oil from the high pressure region to the low flow area trends , mobile one generation, a lower chamber pressure P , P without elevated ends of the thrust acting on the piston F No > F Yes, loss of balance piston rod chamber to move to find a new balance . And so forth, the piston has been moved to an external force barrier to stop. The phenomenon of the maintenance work to the machine brought great impact , replace the cylinder piston "O" ring seal , the machine fault elimination , running back to normal.

Corrosive environment and the mechanical seal granular media

Corrosive environment of the mechanical seal
Some of the mechanical seal in a corrosive environment , then only pay attention to the mechanical seal in the corrosion resistance of each of the part itself , but also to prevent them together may be electrically coupled to produce the phenomenon . Corrosive environment of the mechanical seal , to the attention in the selection of corrosion resistant materials . In addition , you can use externally mounted mechanical cable tie. For particularly corrosive prone to accidents , and can double seal , the introduction of barrier fluid to protect them.
The mechanical seal particulate media
Some mechanical seal may contain solid particles of media work , when the solid particles into the friction face , easy to produce severe wear , resulting in failure of the seal faces soon . Another solid particles may cause the snap ring seals can not move axially , so that the ring can not float, losing compensatory , leading to mechanical seal failure . This more effective approach is to add an external flushing device . Since the flushing fluid into the sealed chamber above the seal chamber pressure medium pressure , thus can effectively prevent the particulate media into the sealed chamber . Also you can use double mechanical seal , seal in the middle of adding liquid cable seals chamber . Can also be used externally mounted mechanical seal.

Kettle mechanical seal installation and use

A mechanical seal for installation
1, check the installation of the mechanical seal models, specifications are correct.
2, check the installation of the host and the associated mechanical seal parts of the dimensional accuracy and geometric accuracy meets the technical requirements of the relationship . Mainly in the following aspects:
( 1 ) Install the mechanical seal parts of the shaft ( or sleeve ) runout tolerance , the shaft ( or sleeve ) surface finish and outside diameter tolerances.
( 2 ) combined with sealed chamber and positioned side facing the shaft gland ( or sleeve ) vertical centerline tolerance .
( 3 ) Install a shaft seal ring ( or sleeve ) of the end portion , the installation of the mechanical seal housing bore and the end portion structure of the chamfer finish.
( 4 ) Mechanical seal the shaft axial displacement when working .
3 , during the installation of mechanical seals should be kept clean and not allowed to use tools beat the sealing element to prevent damage and destruction.
4 , installation, dynamic and static ring surface should be coated with a layer of clean oil and turbine oil . Secondary seal ( including dynamic and static ring seal ring seal ) before installation also need a clean coat of oil or turbine oil, in order to ensure a smooth installation .
5, the stationary ring seal ring in the stationary ring back after the sealed end cap , pay attention not to hurt the stationary ring , to ensure that stationary ring and end caps perpendicular to the centerline , and pay attention to the stationary ring to the back of the anti-rotation slot aligned with anti-rotation pin , but not in contact .
6 , the rotating part of the mechanical seal , relying on the two spring seat and shaft fixing screws and tighten the screws , to ensure that the working length of the spring .
Second, the mechanical seal used:
1, the host before starting , check the mechanical security seal attached devices , cooling and lubrication system is perfect flow.
2, the starting material should be cleaned before the pipeline to prevent rust and impurities into the sealed chamber .
3 , the hand plate moving couplings, check whether the easy axis rotation , if the disc moving heavy, need to check the relevant mounting dimensions are correct.
4 , normal before driving , the need for hydrostatic testing, inspection of mechanical face seals , seals and sealing end caps at the sealing effect , if there are questions , one by one checking resolved.
5 , the host starts , should remain sealed cavity filled with fluid or seal of the media , individually sealed system should start if the cooling water system also began to circulate .
6 , the normal use before normal pressure operation , observe the sealing parts of the temperature is normal, there is no leakage. If minor leaks , can run together for some time, so that a more uniform fitting end to leakage gradually reduced to normal. If running 1-3 hours, does not help reduce leakage , you need to stop and check .
7 , the normal operating conditions , security seal the boost heating respectively slowly , and pay attention to the temperature rise and leaky end , as everything is normal , indicating that you can put into production use.

Sealing butterfly valve with hard seal butterfly valve and use of the distinction

Valve seal means sealing the sides are rigid metallic material or other materials are called "hard seal ." This seal sealing performance is poor, but high temperature, abrasion resistance, good mechanical properties , such as : steel + steel ; steel + copper ; steel + graphite ; steel + alloy ; ( where steel may be cast iron, cast steel, alloy steel may be surfacing , spraying the alloy ) .
Soft sealing : sealing the sides of the metal material side , the other side there is a flexible non-metallic materials are called "soft seal ." This seal sealing performance is good, but not high temperature, easy to wear, mechanical poor , such as: steel + rubber ; steel + PTFE [wiki] polyethylene [/ wiki]; etc. soft sealing seat using a certain strength , hardness and heat resistance of non-metallic materials, good sealing performance, zero leakage can be done , but the life and relatively poor adaptability to temperature . Hard sealed with metal production, sealing performance is relatively poor , despite the manufacturers claim can be done zero leakage. Soft seal on the part of corrosive materials can not meet the technical requirements , the seal can be solved ! These two seals can complement each other , just in terms of soft seal tightness is relatively good , but now it is possible to seal tightness meet the corresponding requirements ! soft seal the advantage of good sealing performance , the disadvantage is easy to aging , wear, short life. Seal long life, but the relative tightness worse than the soft seal .
Their structural differences are mainly the following:
1, the structural differences : soft meter seal butterfly mostly in line more than a single eccentric hard sealing , double eccentric butterfly valve
2 , temperature : soft seal for normal environments. Seal can be used for low temperature , room temperature , high temperature and other environmental
3 , pressure: soft sealing pressure - atmospheric pressure seal can also be used in high-pressure and other conditions
4 , the sealing performance: soft seal and three eccentric hard sealing butterfly valve sealing performance is better, three eccentric butterfly valve in the high pressure high temperature environment can maintain a good seal.
In view of the above characteristics, soft plastic padlock security seals butterfly valve for opening and closing the ventilation and dust piping bidirectional adjustment, water , light industry, petroleum, chemical and other industries. Hard seal butterfly valve used for heating, gas , and coal gas , oil, acid and alkali environment .
With the widespread use of butterfly valves , its easy installation, easy maintenance , simple structure features becoming increasingly apparent. Electric soft seal butterfly valve, pneumatic soft seal butterfly valve, hard seal butterfly valve in more and more places began to replace the electric gate valve, globe valve.

Mechanical seal assembly technology dimension checking

1 ) Measurement of the size of the static ring sealing surface . This data is used to verify the static ring radial width , was elected with different friction materials , hard materials should be higher than the radial width of the friction surface soft big 1 ~ 3mm, otherwise easily lead to hard material embedded in soft material edges face the end go up .
2 ) Check the static ring and the shaft or sleeve of the gap, the stationary ring bigger than the shaft diameter generally 1 ~ 2mm, the ring , in order to ensure the volatility, the internal diameter than the shaft large 0.5 ~ 1mm, to compensate for shaft vibration and skewed,mechanical security seals but the gap is not too large , otherwise it would snap ring seals and cause damage to the mechanical seal performance .
3 ) check the mechanical seal tight force . We usually talk about the mechanical seal tight end than the pressure force that is , face to the right than the pressure is too large , mechanical seal friction surface heating will accelerate the face wear , increased friction power ; too small, easy to leak . Face than the pressure is determined when the mechanical seal design , we can only rely upon assembly clamping force measurement to determine the mechanical seal . Typically the measurement measuring method stationary ring mounted to the vertical distance gland face , pull tight seal and then measuring the gland ring end face to the vertical distance from the difference between the clamping force is the mechanical seal .
4 ) whether the length measurement compensation spring is changed . Spring changes will directly affect the performance of mechanical seal face pressure ratio . Under normal circumstances the length of the spring in the long run will be shortened to compensate for spring mechanical seal ring on the reasons but also because of the centrifugal force and deformation.
5 ) measuring static ring anti-rotation pin sub pin hole depth and length to prevent excessive static ring pin can not be assembled in place. This situation will damage the mechanical seal .

Dynamic seal failure of the pump packing seals

The rich compressibility and resiliency stuffing into the stuffing box gland axial compression force to rely on the radial sealing force transformation , and thus play a role in sealing . This sealing method is called packing seal, this seal packing filler called . Because packing structure is simple , easy to replace , inexpensive, adaptation speed, pressure ,vehicle seals  medium broad and the pump design has been widely used. Transport medium at room temperature , the packing seal packing ring usually has its or high-pressure chamber communicates with the pump , or an external liquid medium with a certain pressure , can play a cooling, lubrication , sealing or flushing effect .
Since packing is a contact seal , so there must be friction and wear problems . The friction and wear size mainly depends on the packing gland clamping force . Pressure can improve the sealing effect , but it will increase the power consumption and the wear sleeve , otherwise it will have a greater leakage. Therefore, the size should be based on the amount of leakage and leakage of the medium temperature of the gland to adjust the pressing force , if necessary, the filler should be replaced or supplemented . Reasonable packing seal leakage is generally 10-20ml/min. When the liquid is introduced from the outside , should ensure that the liquid has good chemical stability ,black cable ties neither the transmission medium pollution pump , not react with the media and solid particles and precipitates , the filler should have a good impregnation and lasting retention, so that we can play a good and long-lasting seal.

Hollow doors to see how to identify seal glance

REVIEW: essence of the problem is that businesses will not necessarily use the same door pocket and door material , solid wood doors with solid wood Door does not mean that it will . If you do a solid wood door with MDF Door , because it does not contain wood fibers , water prone to foaming , can cause deformation of the door frame , so the best time of purchase ask whether the merchant Door and door of a material .
The selection is not solid wooden door ,tamper seal they usually go hand knocking method determines whether solid , but there are not many doors you knock on whether solid, filled with stuffing inside , knocked up with solid doors no difference, but also some owners use to experiment with ways to move the weight , in fact, try not to come out the same effect , because there are a lot of manufacturers put on weight like wood filler to fill in the door , do not come out the same identification .
First, the color of the porter whether their home matches , and then tap , weigh judge the quality of the door . Filler door is generally divided into solid and partially solid, solid filler is certainly heavy , the price also expensive, and some solid relatively light , relatively cheap . However, the market also has some sinister business of some scraps as filler to increase the weight , be careful when consumers buy .
Secondly , you can consult the tightness of the door staff . That is, we say, " seal " , it's in the door pocket and door contact part , feels relatively soft . Formal enterprises will add plastic security seal, thus avoiding the seam after closing there is always a problem .
Again , that is asking Door material, because most doors if there are problems , mainly Door out of the question. Essence of the problem is that the businesses will not necessarily use the same door pocket and door material , solid wood doors with solid wood Door does not mean that it will . If you do a solid wood door with MDF Door , because it does not contain wood fibers , water prone to foaming , can cause deformation of the door frame , so the best time of purchase ask whether the merchant Door and door of a material .

Experts advise beverage bottle Mifengbuyan best comes out cups

Summer is the peak season for sales of beverages , as portable and convenient , bottled drinks have become popular , but recently on the Internet a "thread beverage bottle seal is not enough, easy to cause secondary pollution beverage " message allows many people feel hard to understand : Seal cap how there will be health and safety risks it ? reporters yesterday conducted experiments ...... results: beverage bottle is not sealed ink can penetrate materials : Five drinks , ink, water, washbasin test time: 4 July 14 : 00 to 14:10
Experimental procedure: Yesterday afternoon, reporters from the supermarket to buy five common mineral water, herbal tea , cola and beer, the blue-black ink and water into the basin , and bought from the supermarket five unopened drinks down into the pot to monitor the situation .
Ten minutes later , the reporter will remove all the pot five drinks , open the bottle after the reporter found that all the threads and drink bottle caps inside , stained with ink printing. Experimental results show that , regardless of whether these bottles had opened its mouth , neither the threads of cap security seals sealing , air and water easily through this seemingly "sealed" the bottle into the drink , breed bacteria.
Survey visit : the general public to drink lid
Reporter yesterday visited the survey found that most people are accustomed to drink directly unscrewed the cap , few people would look carefully clean bottle or not . "I usually drink to drink directly open , did not notice the cap usually used in negative net ." The students said light rain . " What beverage bottle tightly as the heel , which the water flow out , things can go outside ? " Public Zhang said.
Experts advise: go best comes cups
A beverage industry veteran , said: consumers unknowingly , bottle screw at the health standards blank manufacturers to reduce costs reluctant to change the bottle molds , etc., are not push the bottle screw receive attention at the health of the important reasons .
In this regard, Chinese Medicine Hospital of Xi'an, director of the Center An Junming treating disease , said beverage bottle itself nylon cable tie sealing effect is not very satisfactory, bacteria can easily through the gap into the bottle cap contaminated drinks , especially in summer , people like to drink on ice , but it easier for bacteria inside the refrigerator into the bottle through the cap , if you frequently drink on ice can easily cause diarrhea. Zhuren proposed open beverage lid , it should first look at the bottle cap is clean around or drink , or to drink on a clean cup to drink , the best way is that the public comes cups water .

Hammer seal leakage and prevention measures

1 when the oil pressure in the low pressure without leakage , causes mounting surface roughness difference ----- improve the surface roughness 3.2 ~ 6.3umry point with low hardness seals
2 larger piston oil ring , each one will be a few drops of oil stroke , causes the dust seal lip scraped film replacement wiper ring patterns.
3 at low temperatures, high temperatures do not leak oil , there are two causes one is too eccentric kind is inappropriate choice of seal materials , selection of cold seals can solve the problem .
The second category seals are not normal circumstances .
1 main oil seal surface hardening , the sliding surface cracks ; reason ----- abnormal high pressure is too high.
2 main oil seal surface hardening , the entire seal security seals broken , broken ; reason ---- hydraulic oil deterioration oil abnormally elevated ozone damage resulting from leaking seals .
3 main oil seal wear like a mirror-like surface smooth ; reason ---- Micro tiny stroke era pressure is too high .
4 main oil seal surface of the mirror uneven wear seals have swelling phenomena ; reason ---- eccentric side pressure is too large too large, use of improper oil and cleaning fluid.
5 main oil seal sliding surface for damage and wear scar ; reason ---- plating is poor, there is rust tie rod surface roughness improper selection of materials containing impurities.
6 top of the main oil seal lip scar rupture indentation ; reason ---- chamfer improper assembly , installation, improper storage methods .
7 main oil seal sliding surface indentation ; reasons ---- possession of foreign debris.
8 main oil seal lip cracks cracks ; reason ---- oil improperly, high or low temperature , high speed is too high back pressure , pulse pressure is frequently too large .
9 There are carbonized charred main oil printed cable ties  deterioration ; reason ---- residues generated adiabatic compression of air .
10 main oil seal extrusion heel cracks ; reason ---- pressure, extrusion gap is too large , as when using the support ring installation groove design is unreasonable.

Bimetal engine gasket facing technical problems

 Replace the engine cylinder head gasket is a very difficult job. For many of the technical staff for maintenance plant , doing this work because many times just like in the same nightmares . If a car for the first time a replacement cylinder head gasket , there is no good in accordance with the technical requirements , then this car will definitely return at some point this repair factories require repair.
If you do not use the correct cylinder gasket , do not follow the correct methods of operation or did not make the right checks , made ​​the effect of sealing certainly will not be desirable . Gasoline engine cylinder head gasket chamber pressure must be sealed in l000psi (1psi = 6.89kPa) above , the turbocharged diesel engine combustion chamber pressure container seals in '7200psi more. Moreover, cylinder head gasket must be able to withstand over 2000 degrees Celsius . High temperature and pressure in such poor working environment, even the presence of the cylinder head sealing minor defects , will lead to replacement of the engine cylinder head gasket failure of the work . Bimetal engine cylinder block and cylinder head are made of different metal compounds formed , his presence makes the engine cylinder head gasket replacement work has become more complex.
Now used by most bimetal engine includes a cylinder block with cast iron and an aluminum cylinder head . Since different metals and alloys thermal expansion and contraction rates are different, barrier seals so the bi-metallic materials to design a successful engine cylinder head gasket , the gasket of many manufacturers are facing a challenging technical problems.

Detailed construction sealing glue

Building sealing glue is mainly used for building various seams or holes sealed to prevent gas , liquid, solid through and prevent displacement of structural materials in the structure is destroyed, and thus play a thermal insulation, sound insulation, waterproof, security ties dustproof, gas-proof , fireproof, anti-corrosion, shock absorption and prevent accumulation of foreign joint function .
First, the classification of building sealing glue
( 1 ) , as classified according to their composition , a polysulfide rubber, chloroprene rubber, acrylic , polyurethane, butyl rubber, silicone rubber, rubber compound , and other thermoplastic elastomer ;
( 2 ) , according to the construction shape , divided into hot coating type , coating type cold curing reaction -and solvent evaporation , etc.
( 3 ) , according to use is divided into windows and doors , caulking to use, waterproof shockproof , precast wall with an equal .
Second, the selection basis for building sealing glue
( 1 ) , a good low permeability ;
( 2 ) , filling them with good workability ;
( 3 ) , the substrate is compatible with seams , pollution , bonding stability ;
( 4 ) , the deformation force in the cohesive failure does not occur ;
( 5 ) , at the temperature without excessive permanent deformation , without softening or sticky , security seals no excessive hardening and embrittlement occur ;
( 6 ) , under conditions of use anti-aging , weather-resistant , long service life and reasonable ;
( 7 ) , the displacement ability to meet the requirements ;
( 8 ) , structural bonding displacement capacity ( % ) and modulus strength rational unity.
Third, building sealing glue factors
( 1 ) , the sun UV radiation aging ;
( 2 ) , oxygen, and ozone oxidation ;
( 3 ), water and steam aging ;
( 4 ) , the environment temperature change ;
( 5 ) , wind load, shear force ;
( 6 ) , the loop mechanical ( compression / tension ) load ;
( 7 ) , invasive of air pollution , such as: acid rain, salt spray , etc. ;
( 8 ) , microbes and large organisms , such as fungi .

Transformer oil leakage depends on these points

Specification seals replacement process
For different models and different capacity of the transformer, whether it is flanged or threaded connection, replace the seals must be cleared before connecting surface dust and rust, clean the numbered seals after the seal on both sides coated with sealant ( generally use 609 polymer liquid sealant ) , a period of time until the sealant drying after solvent evaporation , the flange , screw connections are tight .

Improve installation process level , to eliminate because of improper installation caused leakage
Deformation of the flange interface is uneven or misaligned first correction interface dislocation can not be corrected serious cut can be re-welding flange must ensure parallel interface . Installation for compression gasket thickness of 1/ 3 or so .

Quick sealing glue stick plugging plugging
This method is used in transformers tiny leak , drip situation, the transformer radiator wall is thinner , and the method is inappropriate welding plugging leaks can be taken to deal with this method of plugging. Use glue stick plugging plugging , you must completely remove plugging parts of the oil , tamper seal tape patent leather , oxides, exposing the metal color. Then adjusted by the ratio plugging glue for sealing against leakage area until no leakage so far.

O-ring Installation Considerations

First, install the O-ring (O -type rubber seals ) requirements
O-ring during installation (O type rubber seals ) , check the following:
1 whether the introduction of angular drawings sharp edges are chamfered or rounded ;
(2) whether the burr diameter surface contamination ;
3 seals and parts have been greased or lubricating fluid ( dielectric elastomer to ensure compatibility , it is recommended to use a liquid to lubricate the seal ) ;
4 not use greases containing solid additives , such as molybdenum disulfide, zinc sulfide .
Second, manually install the O-ring (O -type container seals) :
1 using a tool no sharp edges ;
(2) ensure that the O-ring (O -type rubber seals ) do not distort , not excessive stretching O-ring (O -type rubber seals ) ;
3 Try to use the auxiliary tool to install O-ring (O -type rubber seals ) , and to ensure correct positioning ;
4 For sealing strip with adhesive into the O-ring (O -type rubber seals ) , not in the joints stretched.
Third, the mounting screws , splines , etc.
1 When the O-ring (O -type security seal labels) After stretching through screws, splines , keyways , etc. , you must use the installation mandrel . The mandrel may be a softer , smooth metal or plastic , do not have sharp edges or burrs .
2 Install clamping screws , tighten the screws should be symmetrical , not according to the direction of tightening sequence .