Safety classification of pneumatic valve and the selection method

Classification is the safety of the mass production of pneumatic valve has spring type and lever type two kinds big. And impulse pneumatic type safety valve, pilot operated safety pneumatic valve, pneumatic valve switching, security, decompression pneumatic valve, pneumatic valve static weight type safety, etc. Pneumatic valve spring type safety relies mainly on the spring force and work, spring loaded safety in pneumatic valve is closed and not closed, usually inflammable, explosive or toxic medium should choose enclosed, steam or inert gases can choose not enclosed, in the spring loaded safety pneumatic valve with a wrench and not with a wrench. Spanner role is mainly check the pneumatic disc flexibility, sometimes also can be used as a manual emergency pressure relief, as shown in figure. Pneumatic valve lever type safety relies mainly on the lever and weight and the power of the work, but as a result of pneumatic valve lever type safety product large tend to limit the scope to choose. At high temperature to choose the safety of pneumatic valve with the radiator. Security are the main parameters of pneumatic valve displacement, the displacement is determined by the pneumatic valve seat diameter and pneumatic valve opening, the opening height is different, is divided into tiny qi type and whole qi type two kinds. Tiny qi type refers to the opening height of pneumatic pneumatic valve seat throat diameter / ~ l /. All rev type refers to the opening height of pneumatic pneumatic disc/seat throat diameter. Safety is determined by the operating pressure pneumatic valve selection of pneumatic valve nominal pressure, is determined by the operating temperature safety pneumatic valve using temperature range, the safety of the calculated by pneumatic valve spring constant pressure value of the decision or lever of constant pressure range, then determined according to the working medium security material and structural type of pneumatic valve, pneumatic valve discharge capacity calculated according to the safety security the throat area of pneumatic valve. The following general rules for safety pneumatic valve selection. （ l） Hot water boiler is not closed with a wrench is commonly used in micro and pneumatic valve type safety. （ ） Steam boiler or steam pipeline in not normally closed with a wrench and all pneumatic valve type safety. （ ） The incompressible liquid medium such as water generally use safety mini rev type pneumatic valve closed, or use the safe discharge of pneumatic valve. （ ） High pressure water supply with normally closed all rev type pneumatic safety valve, such as high pressure feed water heater, heat exchanger, etc. （ ） Gas compressibility, such as medium with normally closed all rev type pneumatic safety valve, such as gas storage, gas pipelines, etc. （ ） E general use static weight type steam boiler safety pneumatic valve. （ ） Large diameter, large displacement and high pressure system with general pulse pneumatic valve type safety, such as desuperheating decompression device, such as power plant boiler, as shown. （ ） The train transport liquefied petroleum gas tank car, car tank, storage tank and so on general pneumatic valve with built in security, as shown. （ ） Tank roof generally use pneumatic hydraulic safety valve, should be used with breathing pneumatic valve. （ ） Underground drainage or gas pipeline pilot operated safety is commonly used in pneumatic valve, as shown. （ ) Liquefied petroleum QiZhan liquid-phase reflux tank pump discharge line security reflux is commonly used in pneumatic valve. （ ) May produce negative pressure in the process of negative pressure or operating systems generally use pneumatic vacuum negative pressure safety valve. （ ) Back pressure volatile and toxic flammable pipeline system for container or pneumatic valve bellows is commonly used in security. （ ) Medium to low freezing point systems generally use heat preservation jacket type safety pneumatic valve.