Debug method of pneumatic valve

Pneumatic valve positioner features: pneumatic valve positioner and actuator constitute control unit and a variety of regulating valve connection after debugging installation, pneumatic control valve. Pneumatic valve positioning is used in various industrial automation process control field. Pneumatic control valve factory, locator and control valves are done calibration, but often after loaded on the pipeline valve needs to make another calibration, conventional calibration method is: 5 points calibration is 4 ma, ma, ma, ma, 20 ma, in the case of 12 ma locator stem in a horizontal position, the other groups of signal valve position should be in % 0, 25, respectively 75% and 100% of stroke, and feedback rod rotation Angle is less than plus or minus 45 degrees. Can separate to zero and full of deviation adjustment screw corresponding modification, under normal circumstances if the valve stroke and a given signal corresponding calibration done. Electric butterfly valves, electric gate valves, electric valve when the valve is closed a major problem is how to achieve the full load tightly closed valve seat. The usual method is to calibration of the valve, so that the closed parts ( Such as the plug, the diaphragm, valve plate, etc. ) To locate on the seat, not confirm whether closed parts completely depend on the seat. In order to maintain design leakage, avoid sealing surface from corrosion, must design the proper sealing load. Single-acting pneumatic actuators are usually adopts diaphragm design. Adopts this kind of design method, using the spring seat load can be reduced, and can withstand all the closure pressure. The typical double-acting pneumatic actuator piston design. Adopts this kind of design method, and the diaphragm type design, supply pressure don't need to limit, in order to achieve high closure pressure, full load supply pressure can be applied. For piston type design, the higher the pressure, stability and control, the better the sensitivity of the valve.