How many lead seals should there be on the safety valve?
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This post was last edited by Catalyzing a Grain on 2018-11-8 at 15:32. During routine inspections, there should be () lead seals on the safety valve. a、2 b、3 c、4 d、5 The answer is two. Isn’t there a manual valve in front of a normal safety valve? Why are there two seals?
One is used to determine whether the safety valve has activated; when the safety valve activates and there is a change in its displacement, the seal is broken
Lead seals should be applied to both the front and back of the safety valve; those that are in use should have lead seals installed on both their front and back sides； The spare one is front-close and back-open, with a lead seal.
If manual isolation valves are to be installed before and after the safety valve, strictly speaking, lead seals should not be used; instead, locking or unlocking mechanisms should be employed.
Dude, why is the backup rear valve open?
Both the inlet and outlet manual valves of the safety valve must be sealed with lead seals
Manual valves before and after the safety valve, as well as bypass valves, need to be installed. In some cases, the outlet of the safety valve leads directly to the atmosphere; in such cases, only one valve needs to be installed. It mainly depends on the design of the system – as long as the safety valve functions properly, that’s sufficient
Prevent pressure buildup caused by leakage in the front valve, which could trigger the safety valve to activate
What I want to know right now is: which standard requires that lead seals be installed on the manual valves before and after the safety valve? I know that such seals should be used, but I’m not sure which standard mandates this. If anyone knows, please let me know. Thank you.