Safety valve fault diagnosis and repair

1. The reason why this condition is not opened when the specified pressure is reached is that the constant pressure is not allowed. The amount of spring compression or the position of the weight should be readjusted; the valve flap sticks to the valve seat. The safety valve shall be manually deflated or drained periodically; the leverage of the lever-type safety valve is jammed or the hammer is moved. The weight position should be readjusted and the lever should move freely.

2, less than the prescribed pressure is mainly open pressure is not allowed; spring aging elasticity decreased. Tighten the adjusting screw or replace the spring properly.

3, after the discharge valve does not return to the seat This is mainly spring bending valve stem, valve disc installation position is not correct or was caused by the stuck. Should be re-assembled.

4. The frequency jump or vibration of the valve is mainly due to the too high spring stiffness. Should use a spring with appropriate stiffness; improper adjustment of the adjustment ring will make the pressure in the seat back too high. The position of the adjusting ring should be readjusted; the discharge pipe resistance is too large, resulting in excessive discharge back pressure. The discharge pipe resistance should be reduced.

5. The pressure continues to rise after exhausting. This is mainly because of the safety discharge volume of selected safety valve discharge equipment. The appropriate safety valve should be selected again; the stem centerline is not correct or the spring is rusted, so that the valve disc cannot be opened to The height should be re-assembled valve stem or replace the spring; exhaust pipe cut enough, should be taken to meet the safety discharge area of ​​the exhaust pipe.

6. Safety Valve Leakage Under normal working pressure of the equipment, leakage beyond the allowable level occurs between the disc and the sealing surface of the valve seat. The reasons are: There is dirt between the valve flap and the sealing surface of the valve seat. Use a lifting wrench to open the valve a few times to flush away the dirt; the sealing surface is damaged. Should be based on the degree of damage, grinding or grinding after grinding method to repair; valve stem bending, tilting or deflection of the lever and fulcrum, so that the spool and valve disc misalignment. Should be reassembled or replaced; spring elasticity reduced or lost elasticity. Replace the spring and readjust the opening pressure.