Soft and hard seal butterfly pneumatic valve

hard seal, seal on both sides of all is the metal material or other hard materials is referred to as' hard seal. The seal of the seal is poorer, but high temperature resistance, wear resistance, good mechanical energy. Such as: steel + steel; Steel + copper; Steel + graphite; Steel + alloy steel; （ The steel may also be cast iron, cast steel, alloy steel can also be surfacing welding, spraying alloy) 。 Soft seal: seal on both sides of a side is the metal material, on the other side there is a play of nonmetal materials are known as' soft seal. Can the seal of the seal is good, but not high temperature resistant, easy to wear and poor machinery. Such as: steel + rubber; Steel + [four fluorine wiki] Polyethylene [ / wiki] ; And so on. Soft seal refers to seal the side is to use low hardness material, in general, soft seal USES a certain strength, hardness and heat resistance of non-metallic materials, sealing good, can achieve zero leakage, but with poor life and adaptation to temperature hard seal made of metal can seal is relatively poor, despite the manufacturers claim to achieve zero leakage. Soft sealing materials with corrosion on part can't meet the technological requirements, hard seal can solve! The two seal can complement each other, in terms of seal soft seal is relatively good, but now hard seal seal can also meet the requirements of corresponding! Soft seal has the advantage of seal can good, defect is easy ageing, wear and short service life. Hard seal service life is long, but relatively worse than soft sealing seal.