Answer: (1) Fault phenomenon. The safety valve fails to open automatically.
(2) Cause analysis.
1) The spring adjustment pressure of the spring-type safety valve is too large and should be readjusted;
2) The sealing surface is contaminated by the medium or crystallized to cause adhesion or rust;
3) The gap between the valve stem and the bushing is too small;
4) The spring is permanently deformed.
(3) Elimination method.
1) Readjust the safety valve;
2) Blow or grind the sealing surface, and perform a manual exhaust test to eliminate the problem;
3) Appropriately increase the gap between the valve stem and the bushing;
4) Replace the spring.