The characteristics of the pneumatic valve soft seal and hard seal

hard seal and soft seal can complement each other, as for the sealing soft seal is relatively good, but now hard seal sealing can also meet the corresponding requirements, the advantage of soft seal is sealed performance is good, defect is easy ageing, wear and short service life. Hard seal service life is long, but the sealing is relatively worse than soft seal.
soft seal: seal on both sides of a side is the metal material, on the other side is elastic non-metallic materials known as' soft seal. This seal sealing performance is good, but not high temperature resistant, easy to wear and poor machinery. Such as: steel + rubber; Steel + four fluorine polyethylene, etc.
soft seal refers to seal the side is to use low hardness material, generally speaking, the soft seal seat has a certain strength, hardness and heat resistance properties of non-metallic materials, sealed performance is good, can achieve zero leakage, but life and adaptability to temperature with poor hard seal made of metal sealing performance is relatively poor, despite the manufacturers claim to achieve zero leakage. Soft seal part of corrosive material can't meet the technological requirements, hard seal can solve!
hard seal, seal on both sides of all is the metal material or other hard materials is referred to as' hard seal. This seal sealing performance is poor, but high temperature resistance, wear resistance, good mechanical performance. 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) 。