ESD valve closing time
ESD valve closing time
(OP)
I have often used a closing time of max. 20 seconds for ESD valves. Are there anyone here who knows a reference for this value (closing time for an ESDV?)
Best regard¨s
Morten
Best regard¨s
Morten





RE: ESD valve closing time
Analysis, Design, Installation, and Testing of Basic Surface Safety Systems for Offshore Production Platforms, Appendix C - Support Systems C.2.1.4. "The time it takes for any safety device (e.g. PSH, BSL, ESD station, etc.) to effect component or platform shutdown should not exceed 45 seconds."
RE: ESD valve closing time
Thank you
Morten
RE: ESD valve closing time
I have seen a huge volume bottle to close a valve (I think 6", maybe 4") in little over 5 seconds.
I have seen others where 45 seconds probably is more than enough.
"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
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RE: ESD valve closing time
My casual observation is that the closing time for ball valves requires about one second per inch. As you approach the 24-inch size you should be using quick exhaust devices to meet the 45-second rule. Also, the actual process pressure impacts the closing time. A 36-inch full port ball valve may close within less than 45-seconds during commissioning then actually close in 75-seconds against 1200 psig.
API RP 14C lacks opening time criteria.
RE: ESD valve closing time
It comes down to a risk management situation. WHat is the likelihood adn consequence of an action. Engineering design will follow from the analysis.
RE: ESD valve closing time
Sometime "worst case" is a fast closing time (surge e.g.) sometime the long closing time may be a problem (overpressure vented inventory etc.).
But the ansver from JLSeagull was what I was looking for (just couldnt remember the reference).
Best regards
Morten