Analysis of reduced pressure pneumatic valve static sealing fault study 2

prevent the scratch. To reduce the o-rings in the assembly process and sealing surface friction.
the function of reduced pressure pneumatic valve is to inlet pressure is lower than the inlet pressure, as an important component in the hydraulic system. Adhere to the inlet pressure is stable, not affected by the influence of inlet pressure and flow; Once the leak, not only affect the normal production, also caused the loss of hydraulic oil, pollution of the environment; Marine hydraulic system, the reduced pressure pneumatic valve as the main control components, the importance of its sealing is more obvious
found reduced pressure pneumatic valve pressure regulation chamber internal oil in connection and the joint of pneumatic valve leakage phenomenon; In the process of vacuum pneumatic valve open repair, reduced pressure in the process of the operation of the pneumatic valve. Found connected set of fastening connection thread on the solidification of gel formation of concave and convex surface, and o-rings have deformation and leakage passage formation, seriously affected the connections between sets of pneumatic valve body and sealing. The analysis of the sealing problem of

the reduced pressure of the pneumatic valve connection set and pneumatic valve seal is mainly rely on the connection between the sleeve and pneumatic valve body wall to seal o-rings for weeks, after analysed and relevant experts. Once the seal effect, its external leakage is to prevent the leak check assembly and analyzed, the connection of seal between the pneumatic valve body and thought to exist the following problems.
the reduced pressure pneumatic valve assembly, pneumatic valve sealing surface is not sealed. Due to the reduced pressure pneumatic valve connection set and pneumatic relies mainly on the threaded connection between the valve body; In order to prevent the loose thread. Connected set of external thread fastening daub glue, fastening adhesive overflow to the o-rings ring sealing surface, after fastening glue solidification formed on the surface of the seal uneven appearance, formation leakage passage, and make the untight seal o-ring inside and outside, left a hidden danger for the oil leakage.
o-ring seal failure. At present, the o-rings compressed volume is low. Connection between sets of pneumatic valve body and the specifications of the o-rings for phi. mmφ. The mm for seal groove depth. The compression ratio of mmO type circle is. %, static seal compression rate is far lower than the normal theory % ~ %, effectively for the sealing surface can't seal, resulting in seal failure.
although the seal application form common seal form its own disadvantages too. Reduced pressure pneumatic valve's connection and pneumatic valve body between the seal completely rely on the circumferential compression of o-rings in circumferential sealing. But strict in assembly operation. Assembly, the need to keep on o-rings and circumferential sealing surface vertical condition, otherwise, the o-rings in circumferential direction easily into oval, o-rings and sealing surface cannot be effective contact, seal failure in the end. The o-rings after checking, found that the o-rings have Nick, the outer periphery of formation oil leakage channels.
O ring together with the sealing face turning, o-rings and sealing surface friction force is too large. Because in the process of the device. Due to the hardness of o-rings is small relative to the sealing surface, easy to scratch, leakage is to occur.
impact pressure pneumatic valve's connection and pneumatic valve body between the oil leakage of the important factors, the connection between sets of pneumatic valve body and seal the above question. So the measures to solve the problem should be around the problem.
the measures to solve the problem of seal
from aspects put forward the measures to solve the problem. On the above analysis of the reduced pressure pneumatic valve oil leakage.
check surface roughness, improve the quality of the sealing surface. The connection and fastening on the surface of the pneumatic valve sealing glue clean. Review of the seal face size; Improve the o-rings and the sealing surface sealing effect.
so as to improve the surface area of the sealing face of the o-rings. To ensure that the o-ring compressed volume. The connections between sets of pneumatic valve body and the size of the o-rings by phi. mmφ. Mm to phi phi mm mm made by the compression of o-rings. Increased to % %.
on certain level can prevent the leakage of oil; But can not fundamentally solve the o-rings leakage hidden trouble; Therefore, increase the end face seal. Despite more than improve sealing surface quality and increase the amount of compression o-rings. , on the basis of the above measures, the connection and the axial direction of the pneumatic valve and then increase the end face seal, groove depth of. Of the specifications of the mmO ring for phi. Mm phi MMMM compressed volume as %. The advantages of end face seal is: o-rings and sealing surface contact, improve the sealing effect.
with clean lubricating oil daub on the o-rings and sealing, reduce the friction between the o-rings and sealing surface. Assembly connection and pneumatic valve body. Reduce the friction resistance, prevent scratches o-rings. Sealing effect in modified

the quality of the seal o-rings. Connection set and pneumatic valve sealing surface quality was improved.
sealing effect to further improve. Amount of compression o-rings.
fundamentally solved the problem of the reduced pressure pneumatic valve leakage. Increase the end face seal.