Hydraulic pneumatic valve sealing technology and analysis

the service life of hydraulic support all kinds of hydraulic pneumatic valve is very low, foreign way and solution is to improve the filtering precision of the system and improve the quality of the emulsion, but it is not big. Therefore, sealing technology is to improve the service life of hydraulic pneumatic valve in hydraulic support of the key.
hydraulic pneumatic valve is used to control the hydraulic system of the oil pressure, flow and liquid flow direction, is a kind of operation automation components with pressure oil, it is for oil pressure of pneumatic valve control, usually with combined with pressure pneumatic valve, hydraulic support is the supporting equipment in coal mining machinery, after overhaul in downhole can generally be used, but the service life of hydraulic support all kinds of hydraulic pneumatic valve is very low, long months, only a few short weeks.
went to test the working liquid contains impurities is the cause of the damage the sealing. There is friction between the sealing element impurities caused the leakage of pneumatic valve. Foreign thought through the corresponding class of hydraulic components of the corresponding precision filter. They think mu M pump seal element, if the filtration precision filter for M/mu, life than the mu M times.
with the development of hydraulic support technology, the use of pneumatic valve performance and service life of the pneumatic valve put forward higher requirements, but with pneumatic valve hydraulic support, the work environment is very bad. Packing element damage is the main factor of working liquid impurities, grinding between these impurities in the sealing element, make the pneumatic valve from leaking. In the mining face, the total length of the tubing meters, joint pin up to multiple, tank no special dust-proof facilities. There are a large number of floating impurities in emulsion, and pneumatic valve chamber in the bottom of a column cylinder, leave more pulverized coal and rock grains and iron filings. In hydraulic and pneumatic pneumatic valve core seat, because open shutoff is frequent, high liquid velocity, seal failure soon. Proved less support liquid of hydraulic system pollution of impurities, it is very difficult, someone once envisaged in the emulsion pump station adopts high pressure filter, in each bracket inlet at the same time increase the small filter. But was quickly blocked in the work, form.
at present, on the other hand, when a mesh filters and magnetic filter conditions, the total capacity of emulsion tested by pneumatic valve, pneumatic valve opening and closing times and to measure the life of pneumatic valve. But in fact indoor type testing and downhole working results vary widely. Therefore, you need to use the new, strong ability to resist pollution, is suitable for downhole working conditions of seal.
the history and status of hydraulic pneumatic valve sealing materials pneumatic valve core and pneumatic seat contact surface leakage, is the result of liquid molecules into work. Affect the sealing effect is the main reason of the pneumatic valve core and pneumatic seat contact pressure, roughness and differential pressure. When the pneumatic valve core and pneumatic seat junction plane with P compaction force, working liquid molecules to force into F, sealing material can produce elastic deformation. If the seal deputy resistance is greater than the molecular repulsive force, the sealing effective, otherwise will form the leak. Early hydraulic support, there is no other sealing measures between kinematic pair, is direct contact with the metal seal, requiring the seal contact surface, has high machining accuracy, otherwise must increase the adhesion strength of the seal, and make the contact surface to produce plastic deformation, plug leak path.