Choose pneumatic valve sealing surface material six factors should be considered

pneumatic valve sealing surface is one of the most important surface, sealing surface quality directly affect the sealing material on the surface of a pneumatic valve life, is to ensure that in one of the important factors on the quality of the sealing surface. Therefore, when the choice, should consider the pneumatic valve sealing material on the surface of the following factors: (1) corrosion. Sealing face of the 'corrosion' role in the media, the process of surface damage. If the surface is affected by such damage, seal cannot be guaranteed, therefore, sealing materials must be resistant to corrosion. Corrosion resistant material depends on the material and its extreme chemical stability. (2) the scratch. 'From scratch' in the process of material loss caused by friction sealing surface relative movement. The damage will inevitably lead to seal face destruction, therefore, sealing surface material must have good wear resistance, especially the pneumatic valve. Scratch resistant material often depends on the internal properties of the material. (3) corrosion resistance. 'Erosion', through the sealing face through the media, the destruction process of sealing surface. In the high temperature, high pressure steam throttling pneumatic valve seal more evident in the media, as a result, the destruction of the scouring effect using damage are also the important condition of the sealing surface of materials. (4) there should be a certain hardness, and according to the lower temperature, hardness of the workplace. (5) the sealing surface and bulk materials should as the coefficient of linear expansion, more important is to set up the loop structure, in order to avoid high temperature stress, and easy to cause additional loose. 6. Under the condition of high temperature, have enough resistance to oxidation, thermal fatigue and thermal cycle. In the current situation, find the sealing surface material is a very difficult thing that accords with a requirement completely, and use only according to the different pneumatic valve, focused on satisfy certain requirements. For example, in the media use pneumatic valve, should pay special attention to the sealing surface erosion capacity requirements; Medium solid impurities, should choose high hardness material sealing surface.