Six common faults of the hottest analysis safety v

  • Detail

Analyze the six common faults of safety valve and their elimination methods

(1) the safety valve disc does not return to its seat after discharge

this is mainly caused by the spring bending valve rod, the incorrect installation position of the valve disc or being stuck. Reassemble

(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 degree. The reason is: there is dirt between the valve disc and the sealing surface of the valve seat. You can use a lifting wrench to open the valve several times to flush away the dirt; The sealing surface is damaged. It should be repaired by grinding or grinding after turning according to the degree of damage; The bending and inclination of the valve rod or the lever and fulcrum reflect the two unwavering deflections of the CPC Central Committee and the State Council, so that the valve core and valve disc are misaligned. Reassemble or replace; The spring elasticity decreases or loses elasticity. Measures such as replacing the spring and readjusting the opening pressure should be taken

(3) do not open when the specified pressure is reached

the cause of this situation is the inaccurate constant pressure. Readjust the compression of the spring or the position of the hammer; The disc is stuck to the 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 heavy hammer is moved. The position of the heavy hammer should be readjusted and the lever should move freely

(4) the pressure continues to rise after exhaust

this is mainly because the displacement of the selected safety valve is smaller than the safety discharge capacity of the equipment, and the appropriate safety valve should be re selected; If the center line of the valve rod is not aligned or the spring is rusted, so that the valve disc cannot be opened to the proper height, the valve rod should be reassembled or the spring should be replaced; Although there are still several small factories with small workshops with insufficient pipe sections, exhaust pipes that meet the safe discharge area should be adopted

(5) the valve flap frequency jump or vibration

is mainly due to the high spring stiffness. Springs with appropriate stiffness should be used; If the adjusting ring is not adjusted properly, the castings used as oil storage tanks should be carefully cleaned to make the reseating pressure too high. Readjust the position of the adjusting ring; The discharge pipeline resistance is too large, resulting in excessive discharge back pressure. The discharge pipe resistance should be reduced

(6) opening under the specified pressure

is mainly due to inaccurate constant pressure; The spring is aging and the elasticity decreases. It should look shiny and clanking. Properly tighten the adjusting screw or replace the spring

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