The main cause of safety valve failure is improper design, manufacture, selection or use. If these faults are not eliminated in time, they will affect the efficiency and service life of the valve, and even fail to play a role of safety protection. Common faults and solutions are as follows:

(1) leakage. Under the normal working pressure of the equipment, the leakage between the valve disc and the sealing surface of the valve seat exceeds the allowable level. The reason is: there is dirt between the valve disc and the sealing surface of the valve seat. The lifting wrench can be used to open the valve several times to wash away the dirt; the sealing surface is damaged. According to the degree of damage, it shall be repaired by grinding or grinding after turning; the valve rod shall be bent, tilted or the lever and fulcrum shall be skewed to make the valve core and disc misplaced. It shall be reassembled or replaced; the spring elasticity shall be reduced or lost. The spring shall be replaced and the opening pressure shall be readjusted.

(2) Do not open at specified pressure. The reason for this is the inaccurate constant pressure. The compression amount of the spring or the position of the heavy hammer shall be readjusted; the disc and the valve seat shall be stuck. The safety valve shall be subject to manual air release or water discharge test regularly; the lever of the lever type safety valve is stuck or the heavy hammer is moved. The position of the hammer should be readjusted and the lever should move freely.

(3) Open under specified pressure. The main reason is that the constant pressure is not accurate, and the aging spring force decreases. The adjusting screw shall be tightened properly or the spring shall be replaced.

(4) The pressure continues to rise after venting. This is mainly due to the safety discharge capacity of the selected safety valve with small displacement and flat equipment, and the appropriate safety valve should be re selected; the valve rod center line is not correct or the spring is rusted, so that the valve disc cannot be opened to the proper height, so the valve rod should be re assembled or the spring should be replaced; if the section of the exhaust pipe is not enough, the exhaust pipe conforming to the safety discharge area should be adopted.

(5) The valve disc does not reseat after discharge. This is mainly due to the spring bending stem, valve disc installation position is not correct or stuck. It should be reassembled.

(6) Valve disc frequency jump or vibration. Mainly due to the spring stiffness is too large. The spring with proper rigidity should be used; the adjustment ring is not adjusted properly, so that the reseating pressure is too high. The position of the adjusting ring should be readjusted; the resistance of the discharge pipe is too large, resulting in excessive discharge back pressure. The discharge pipe resistance shall be reduced.