Common faults and reasons
First is safety valve leakage. The main reason is (1) core and valve seat contacting surface is not tightly; (2) core and valve seat contacting surface has dirt; (3) stem deflection.
Second is safety valve is not open when it gets to the required pressure. The main reason is (1) core sticks the seat, it can be done manually to exclude the exhaust test; (2) spring-type safety valve spring adjust pressure is too large, should be re-adjusted; (3) lever-type safety valve heavy hammer backward movement, should move heavy hammer to original constant pressure position, with limited motion screw fastening.
Third, safety valve opens without requiring the pressure. The main reason is (1) spring-loaded safety valve spring pressure adjustment is not enough, spring failure or elastic not enough to be re-transferred or re-change safety valve; (2) lever-type safety valve heavy hammer moves forward, should be moved heavy hammer to the original constant pressure position, with limited motion screw fastening.
