Pneumatic control valve is what could be happening?

Pneumatic control valve is what could be happening? A) The pneumatic - valve vibration. Pneumatic control valve in He Kaidu under vibration. (1) to support the instability; (2) there is vibration source near; (3) the valve core and bushing wear. The pneumatic - valve full close position near the end of the vibration. 1) pneumatic - valve to choose large, often used in the small open degrees; (2) the flow direction of medium single-seat valve to close in the opposite direction. 2) Pneumatic control valve action is slow. The valve stem in one direction only slow action. 1) pneumatic diaphragm actuator of the diaphragm leakage; (2) in the actuator type O seal leakage. The valve stem have dull phenomenon in the reciprocating motion. (1) the body with sticky content block; (2) a asbestos packing ptfe or graphite packing metamorphic sclerosis lubricating oil dry; (3) packing too tight, the friction resistance increases; (4) frictional resistance due to the valve stem is not straight; 5. No locator pneumatic pneumatic regulator can also lead to action. 3) Pneumatic control valve leakage increase. Valve leakage when fitted. In (1) valve core is frayed, severe leakage, (2) valve set off is lax. The short of full closed position. (1) the medium pressure difference is too big, small rigidity, actuator valve closed lax; (2) valve with foreign body; (3) bushing sintering. 4) Smaller flow adjustable range. The main reason is that the valve core is smaller corrosion, so that the minimum flow of adjustable. Pneumatic pneumatic - valve fault phenomenon and reason, can suit the action to solve. Increase pneumatic - valve throttle clearance method such as solid particles in the medium or washed off in pipe welding slag and rust due to pass the throttle mouth such as congestion, jam, such as fault, can convert the throttle gap big throttling parts & ndash; Throttling area of a window, open the valve core and the sleeve, rather than the circumference of a circle because of the throttling area of concentration distribution, fault can easily be ruled out. If you are single, two-seat valves can change the plunger type valve core to V mouth valve core, or into a sleeve valve, etc. Such as have a pneumatic control valve in a chemical plant often stuck, recommend to switch to the sleeve valve, problem be solved immediately.