Safety valve of the common faults and processing methods

Safety valve is the main reason of the design, manufacture, selection or improper use. These failures if not eliminate, in time will affect the effect of the valve and life, even can not ensure the safety protection. The common faults and processing methods are as follows: ( 1) Leaks. In the device under normal working pressure, the valve flap and valve seat sealing surface leakage occurred more than allow degree between. The reasons are as follows: between the valve disc and valve seat sealing surface dirt. Can improve wrench open valve a few times, use the dirt away; The sealing surface damage. Should be used according to the damage degree, grinding or turning after grinding method to repair; The valve rod bending, tilt or lever to pivot deviation, make the valve core and valve disc displacement. Should be repackaging or replacement; Spring elasticity decreased or loss of elasticity. Should be taken to replace the spring, readjust the opening pressure, etc. ( 2) To the provisions of the pressure is not open. The causes of this situation is a constant pressure is not allowed. Should readjust the amount of compression spring or the position of heavy hammer; The valve disc and valve sticking. Should be conducted on a regular basis safety valve for manual vent or drain test; Lever type safety valve lever stuck or heavy hammer has been moved. Should be to adjust heavy hammer position and make the lever movement. ( 3) Pressure to open less than regulation. The constant pressure mainly inaccurate; Spring aging elastic decline. Should be appropriate tightening the adjustment screw or replace the spring. ( 4) After the exhaust pressure continues to rise. This is mainly because of the safety discharge capacity of safety valve displacement xiaoping equipment, should be to choose a suitable safety valve; Valve stem midline deviation or spring rusting, the valve disc to open due to high, should be reassemble valve rod or replace the spring; The exhaust pipe section is not enough, should be taken to meet safety discharge area of the exhaust pipe. ( 5) After the discharge valve disc not to return. Mainly spring bending the valve rod, valve valve installation position is not straight or stuck. Should be reassembled. ( 6) The valve disc jump or vibration frequency. Is mainly due to the spring stiffness is too big. Should convert the appropriate spring stiffness; Improper adjustment ring, make the back pressure is too high. Should readjust the adjusting ring position; Drain line resistance is too large, cause excessive emissions back pressure. Should reduce the discharge pipe resistance.