Common Faults and Troubleshooting of Spring Safety

2、 Common Faults and Troubleshooting of Spring Safety Valve

(1) The valve disc does not return to the seat after exhausting: this is mainly caused by the bending of the valve rod of the compression spring, the incorrect installation position of the valve disc or the seizure. It should be reassembled.

(2) 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 that there is dirt between the valve disc and the sealing surface of the valve seat. The valve can be opened several times with a lifting wrench to remove dirt; The sealing surface is damaged. According to the degree of damage, it shall be polished or repaired after rotation; The valve stem is bent or inclined, or the lever and fulcrum are inclined, so that the valve core and disc are misaligned. It shall be reassembled or replaced; Spring elasticity shall be reduced or lost. Replace the spring and adjust the opening pressure.

(3) Do not open under the specified pressure: the reason is that the constant pressure is not accurate. Readjust the compression amount of the spring or the position of the weight, and clamp the valve disc and valve seat. 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 weight moves. The position of the hammer should be readjusted and the control lever should move freely.

(4) The pressure continues to rise after exhaust: this is mainly because the selected safety valve has small displacement and flat equipment, so the appropriate safety valve should be re selected; If the valve stem centerline is incorrect or the spring is rusty, so that the valve disc cannot be opened to the proper height, the valve stem shall be reassembled or the spring shall be replaced. If the exhaust pipe section is not enough, the exhaust pipe conforming to the safety relief area shall be used.

(5) The frequency of valve disc jumps or vibrates: mainly because the spring stiffness is too large. Spring with proper rigidity shall be used; The adjustment ring is improperly adjusted, resulting in too high reseating pressure. The position of the adjusting ring should be readjusted. The discharge pipe resistance is too large, resulting in excessive discharge back pressure. Reduce the resistance of discharge pipe.

(6) Opening under specified pressure: the main reason is that the constant pressure is inaccurate and the aging spring force decreases. The adjusting screw should be tightened or the spring should be replaced.

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