Cock structure characteristics and application of pneumatic valve

（ ） Cock dc by pneumatic valve fluid, small resistance, convenient, rapid opening and closing.
　　
　　（ ） Cock pneumatic valve in the pipeline is mainly used for cutting, and change the flow direction of medium. It is easy to adapt to the multi-channel structure, and a pneumatic valve can have two, three or even four different flow channel, so that we can simplify the design of the pipeline system, reduce the dosage of pneumatic valve door need some connection accessories and equipment.
　　
　　（ ） Cock pneumatic valve is in the history of the earliest people to adopt pneumatic valve. Because of its simple structure, open and close quickly, Plug/Q turns can complete opening and closing action, convenient operation, small fluid resistance, are still widely used. At present is mainly used in low pressure, under the condition of small and medium temperature is not high.
　　
　　（ ） According to the structural characteristics of cock of the pneumatic valve and can achieve the function of the design, can choose according to the following principles.

(1) used for distribution of medium and change the flow direction of medium, its working temperature is not higher than ℃, nominal pressure PN or less. MPa, no greater than nominal diameter mm, suggest choose path more cock pneumatic valve.

(2) food companies such as milk, juice, beer industry and pharmaceutical equipment and pipeline, advice with austenitic stainless steel, tight pattern conical cock pneumatic valve.

(3) oil field, natural gas field exploitation, the branch pipeline, refining and cleaning equipment, nominal pressure no greater than the Class level, is not greater than the nominal diameter mm, suggested that choose pneumatic valve oil seal type conical cock.

(4) oil field exploitation, gas drilling, the branch pipeline, refining and cleaning equipment, nominal pressure level is not greater than the nominal size Class, no greater than mm, the working temperature is not higher than ℃, suggested that choose pneumatic valve oil seal type conical cock.

(5) in the large chemical industry, containing corrosive medium in the pipeline and equipment, requiring open or closed fast, in the nitric acid can be used for medium teflon sleeve sealing conical cock pneumatic valve; For medium to acetic acid as the base, can choose CrlNilMTi stainless steel with ptfe sealing conical sleeve cock pneumatic valve.

6 in the hvac system in coal gas, natural gas, pipeline and equipment, is not greater than the nominal diameter nm, appropriate chooses packing type pneumatic valve cone cock.