The application of reduced pressure pneumatic valve and selection

the reduced pressure pneumatic valve is by changing the throttling area, change the kinetic energy of the flow velocity and fluid, different pressure loss, so as to achieve the aim of decompression, and rely on the media itself energy control and the adjustment of the control system, pneumatic valve after pressure fluctuations and the spring force balance, make the pneumatic valve after pressure in a certain error range constant automatic pneumatic valves.
a, reduced pressure pneumatic valve selection principle:
. Reduced pressure pneumatic valve inlet pressure fluctuations should be controlled in inlet pressure given value % ~ %, if exceed the scope, reduced pressure pneumatic valve performance will be affected.
。 Often reduced pressure of the pneumatic valve pneumatic valve after pressure Pc should be less than before the pneumatic valve. Times, namely Pc< 。 P。 Decompression of the pneumatic valve each leg spring applies only within a certain range of outlet pressure, beyond the scope of a spring should be replaced.
。 Work in the medium temperature is higher, generally choose guiding type piston vacuum pneumatic valve or guiding type vacuum pneumatic valve bellows.
。 Medium for air or water, Liquid) Occasions, general appropriate chooses direct acting diaphragm vacuum pneumatic diaphragm pressure relief valve or the guide type pneumatic valve.
。 Medium for steam, appropriate chooses the guide piston vacuum pneumatic valve or pilot corrugated pipe pneumatic valve to relieve stress.
。 For operation, adjustment and maintenance convenience, the reduced pressure pneumatic valve should be installed in horizontal pipe runs.
2, the basic properties of the reduced pressure pneumatic valve
( ） Reduced pressure pneumatic valve regulating range: it refers to the reduced pressure pneumatic valve output pressure P adjustable range, meet the precision within the scope of this requirement. Regulating scope mainly related to pressure regulating spring stiffness.
（ ） Relief pressure characteristics of pneumatic valve: it refers to the flow fixed value for g, caused by the input pressure fluctuation characteristics of the output pressure fluctuations. The smaller the output pressure fluctuation, the characteristics of vacuum pneumatic valve, the better. The output pressure must be less than the input pressure - Constant value was basically not changes over the input pressure.
（ ） Reduced pressure pneumatic valve flow characteristic: it refers to the input pressure - Timing, the output pressure changes along with the change of output flow g resistance. G when the flow changes, the output pressure changes as small as possible. Generally the lower the output pressure, which fluctuates according to the change of output flow.
3, the selection of vacuum pneumatic valve
in accordance with the requirements of using the selected decompression pneumatic valve type and voltage regulation accuracy, then choose the size according to the maximum output flow required. MPa. Reduced pressure pneumatic valve
general installation after water air filter, oil mist device or setter, and pay attention to answer against its import and export; Pneumatic valve should relax the knob when not in use, in order to avoid diaphragm often compression deformation and affect its performance.