What will you Inspect of a Safety valve which is fitted on exhaust gas boiler?

1. When overhauling safety valves care must be taken that parts for each valve are kept separate.
2. When dismantled the spring and the spindle should be hung up and sounded by gently tapping with a hammer. It they do not ring true examine for faults.
3.  The valve spindle should be checked for straightness.
4.  Springs should be checked for distortion and the free length compared against makers recommendation.
5. Check that all drains are clear and the easing gear is free.
6.  Chest and vent pipes should be checked for corrosion and stress cracking.
7. The faces of the seat and valve heads should be checked for damage with compare with the maker’s recommendation. If machining is required then should be carried out following makers instructions with due regards to lip clearances and sitting width etc.