(1) The failure of the regulating valve is caused by no signal pressure or rupture of diaphragm, leakage of diaphragm, decrease of diaphragm thrust, sticking valve core on valve seat or bushing, and bending of valve stem. The solution is to connect the signal wire to the air source connector firmly, or replace the diaphragm, straighten the valve stem or replace the valve stem.

(2) The regulating valve is normally operated by the regulating valve, but it does not play an adjustment role. The reason is: the valve core is falling off or the pipeline is blocked. The solution: if the valve core is falling off, the valve core is firmly connected with the valve stem, and the competent department shall be contacted for the pipeline problems to dredge the pipeline.

(3) The action of regulating valve is slow or runout, the reason: aging or drying of sealing packing increases the friction between valve stem and packing, and there are large viscous dirt and blockage and coking in the valve body. Leakage occurs in diaphragm and "O" ring of pneumatic regulating valve. Solution: replace sealing packing, readjust, remove dirt, coking, etc., fasten the membrane head, Or replace the diaphragm, O-ring.

(4) The regulating valve is unstable or vibrated, because: the diameter of the regulating valve is too large, the flow direction of single seat valve medium in the valve is the same as the closing direction, the valve core and guide sleeve are severely worn. The solution: replace the valve with the proper valve diameter, adjust the valve direction, improve the junction surface (grinding) of the electric regulating valve or replace the valve core and guide sleeve.