How to solve the failure of the safety valve?

The main cause of safety valve failure is improper design, manufacture, selection or use. If these faults are not eliminated in time, it will affect the efficiency and life of the valve, and it will not even play a role in safety protection.

Common faults and solutions are as follows:
(1) Leakage. Under the normal working pressure of the equipment, more than the allowable leakage occurs between the valve clack and the sealing surface of the valve seat. The reason is: there is dirt between the valve disc and the sealing surface of the valve seat. You can use the lift wrench to open the valve several times to flush away the dirt; the sealing surface is damaged. According to the degree of damage, the method of grinding or grinding after turning should be used to repair; the valve stem is bent, inclined or the lever and the fulcrum are deviated, so that the valve core and the valve disc are misaligned. Should be reassembled or replaced; the spring elasticity is reduced or loses its elasticity. Measures such as replacing the spring and re-adjusting the opening pressure should be taken.

(2) It does not open when the specified pressure is reached. The reason for this is the inaccurate constant pressure. The compression amount of the spring or the position of the heavy hammer should be readjusted; the disc and the valve seat are stuck. The safety valve should be manually deflated or drained regularly; the lever of the lever-type safety valve is stuck or the hammer is moved. The position of the heavy hammer should be readjusted and the lever can move freely.

(3) Opening under the specified pressure. The main reason is that the constant pressure is inaccurate; the elasticity of the spring is reduced due to aging. The adjustment screw should be tightened properly or the spring should be replaced.

(4) The pressure continues to rise after exhausting. This is mainly because the selected safety valve has a small displacement and the safety discharge capacity of the equipment. The appropriate safety valve should be re-selected; the center line of the valve stem is not correct or the spring is rusted, so that the valve disc cannot be opened to the expected height, and the valve stem should be reassembled Or replace the spring; if the exhaust pipe is insufficiently cut, use an exhaust pipe that meets the safe discharge area.

(5) The disc does not return to its seat after discharge. This is mainly caused by the spring bending the valve stem, the improper installation position of the valve disc, or the being stuck. Should be reassembled.

(6) The valve flap frequency jumps or vibrates. The main reason is that the spring stiffness is too large. The spring with proper stiffness should be used instead; the adjusting ring is not adjusted properly, so that the return 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 resistance of the discharge pipe should be reduced.
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