Security relative term definition of pneumatic valve

nominal pressure, pneumatic valve said security under the state of the maximum allowable pressure, high temperature and the safety of the equipment using pneumatic valve should not be considered under the high temperature material allowable stress reduction. Security pneumatic valve is according to the nominal pressure standard design and manufacture.
opening pressure, also called the rated pressure, pneumatic valve pneumatic disc refers to the safety in operation conditions arise when the inlet pressure, under the pressure, began to have a measurable open height, medium is conditions for continuous emissions by the power of sight or hearing.
discharge pressure: pneumatic disc reach regulation when you start the height of inlet pressure. The cap on the discharge pressure to conform to the demands of the relevant national standards or specifications.
over pressure, discharge pressure and opening pressure difference, usually expressed in the percentage of opening pressure.
back pressure: emissions pneumatic disc to contact with the pneumatic valve seat, after the opening into the inlet pressure to the zero.
opening and closing pressure difference: the difference between the open pressure and back pressure, often with back pressure and the percentage of the opening pressure, said only when open both pressure difference are used to indicate when the pressure is very low.
back pressure, safe pressure of the pneumatic valve outlet.
the rated discharge pressure: the upper limit of discharge pressure prescribed standards.
seal test pressure: the inlet pressure to the sealing experiment was carried out, under the pressure measured by closing a sealing surface leakage rate.
open height: pneumatic disc leave the actual lift in the closed position.
port area: refers to the inlet pneumatic valve is to shut down a sealing surface between the smallest cross-sectional area of flow channel, to the theory of calculating the impact without any resistance capacity.
port diameter, corresponding to the diameter of the port area.
shade area: when the air valve in the pneumatic seat above, in the form of formed between the sealing surface of a cylinder or cone surface shape channel area.
discharge area: pneumatic valve discharge fluid channel, the minimum cross-sectional area. For all security pneumatic valve, discharge area is equal to the port area; For safety mini rev type pneumatic valve, discharge area is equal to the shade area.
the theory of displacement, flow and safety section of pneumatic valve port area is equal to the ideal of the nozzle calculation of displacement.
displacement coefficient, the ratio of the actual displacement and displacement theory.
the rated discharge coefficient, displacement coefficient and reduction coefficient ( Taking. ） The product.
the rated capacity: refers to the actual delivery allowed as a security in that part of the pneumatic valve applicable benchmark.
equivalent calculation of displacement: refers to the condition such as pressure, temperature, dielectric properties and the application of the rated discharge conditions at the same time, the security of the pneumatic valve displacement calculation.
frequency jump: safety pneumatic valve pneumatic disc unusually movement back and forth rapidly, pneumatic disc contact pneumatic seat in the movement.
flutter: safety pneumatic valve pneumatic disc unusually movement back and forth rapidly, pneumatic disc out of touch with pneumatic seat in the movement.