Introduction of pneumatic control valve

1. Application of regulating valve in modern factories The regulating valve is used in conjunction with other instruments to realize the automatic adjustment and remote control functions of flow, liquid level, pressure, temperature and other process parameters and other media such as liquid, gas, steam, etc. in the production process . Among them, the pneumatic membrane control valve is the final execution of the automatic control system. First, the application of the control valve in modern factories

　　 Pneumatic control valve is used in conjunction with other instruments to realize automatic adjustment and remote control of flow, liquid level, pressure, temperature and other process parameters and other media such as liquid, gas, steam, etc. during the production process. Among them, the pneumatic membrane control valve plays a very important role as the final actuator of the automatic control system. The application of the control valve is directly related to the quality and safety of production.

2. Common faults, cause analysis and solutions of regulating valves

(1) The regulating valve does not operate. Reason: There is no signal pressure or the diaphragm is broken, the diaphragm is leaking, the diaphragm thrust is reduced; the valve core and the valve seat or bushing are stuck, the valve stem is bent and other reasons make the regulating valve unable to move. Solution: Connect the signal line and the air supply connector firmly or replace the diaphragm; straighten the valve stem or replace the valve stem.

(2) The regulating valve operates normally, but it has no regulating effect. Reason: The valve core is off or the pipeline is blocked. Solution: If the valve core falls off, connect the valve core and the valve stem firmly, and contact the competent department to clear the pipeline if there is a pipeline problem.

(3) Sluggish or bounce control valve action. Reasons: the aging or dryness of the sealing packing increases the friction between the valve stem and the packing; the valve body contains highly viscous dirt and clogging, coking, etc.; the diaphragm and the "O"-shaped sealing ring are also leaking. Solution: Replace the sealing packing, readjust it; remove dirt, coking, etc.; tighten the membrane head, or replace the membrane and O-ring.

(4) The control valve is unstable or oscillates. Reason: The diameter of the regulating valve is too large; the flow direction of the single-seat valve medium in the valve is the same as the closing direction. The valve core and guide sleeve are severely worn. Solution: Replace the valve with a proper valve diameter; adjust the valve direction; improve the joint surface (grinding) or replace the valve core and guide sleeve.