Safety valve Gagging

[GAL02]

Dear all, Good afternoon !
AS we know for Boiler testing purpose we are doing gagging of Safety valve.
I Search Google for any videos related to it which can put more
light on it but not found.
Can anybody explain in detail or any doc. or video can be share?

Pl. revert.

With regards

 

[LittleInch]

Can you explain in more detail what you're doing.

"testing" can mean many things. If doing this with steam then no, you can't do it.

If you're hydrotesting it after repair and the boiler is physically isolated and your pressure test device has pressure limiting devices then maybe, but there's nothing to go on here.

Is this the same 50+ year old plant / boiler you've been asking questions about before?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Danlap]

Hi GAL02,

IMO your question is more suitable for PSV forum

http://www.eng-tips.com/threadminder.cfm?pid=1203

. Of course some of us in this forum have experiences in safety valve.
Agree with LittleInch in regards with the steam and that you should be clear of what you / your plant intentions are. Currently is not.

For example:
What is the testing pressure medium and temperature (P/T)? How many safety valves are you talking here and type? Is it close loop or to atmosphere?
And is this only testing pressure or you want to adjust the safety valve(s) as well?

See some hint from some expert whom have done this

http://www.eng-tips.com/viewthread.cfm?qid=180240

. Moral of the story, this is a risky job with some uncertainties, be cautious for operator to position themselves when performing this. If your safety valve is open loop, do not position any parts of someones' body in front or near the outlet
some reference for safety valve in general.

http://www.spiraxsarco.com/Resource...ials/safety-valves/types-of-safety-valve.aspx

For gaging as well as adjusting it in relatively safe manner, Trevi-test is one way to do it. similar video by Tru-test

https://www.youtube.com/watch?v=gAwS-tjbLeg

Be cautious that you or the commissioning personnel should correspond both safety valves' setting pressure vs the testing pressure. If its gagged (set the screw to prevent it from opening)at X Psi, then the testing pressure is not advisable to exceed 5% of X. this potentially bent the spindle. And if this happened, as per safety regulation the damage parts shall be renewed with UV stamped (read: original) manufacturer parts (if your safety valve manufacturer and your boiler are referring to ASME).

Kind regards,
MR

https://nosuchvalve.com

All valves will last for years, except the ones that were poorly manufactured; are still wrongly operated and or were wrongly selected

http://www.eng-tips.com/faqs.cfm?&rat1=2&fid=376