Pneumatic valve packing type

packing can be divided into soft and hard packing two kinds:
) Soft packing: department of plant material, namely, hemp, linen, cotton, jute, etc. , or by the minerals, namely asbestos fiber, or by asbestos fiber clip wire inside and outside coated graphite powder such as braided cord, also have pressed into the shape of filler, and the new development of flexible graphite packing materials in recent years. Plant material packing cheaper, often used in low pressure pneumatic valve ℃ below; Mineral filler can be used for the ~ ℃ of pneumatic valve.
in recent years, using rubber o-rings for packing structure in promotes gradually, but the medium temperature limit under ℃. Packing also has a high temperature and high pressure pneumatic valves pure asbestos and flake graphite powder compaction.
　　） Hard packing: made of metal or metal with a mixture of asbestos, graphite packing, and packing, ptfe pressing sintering and forming metal packing use less.