Closure time of ESD valve
Closure time of ESD valve
(OP)
I'm trying to generate some guidelines for closure time of emergency shutdown valves (ball and butterfly type) for an oild and gas client.
Is there any field data specifying actual closure times and giving details of the valve size, duty, process conditions etc. I have been looking intently and cannot find anything. I understand it's dependent on the application but is there any guidance out there at all?
Thanks in advance.
Is there any field data specifying actual closure times and giving details of the valve size, duty, process conditions etc. I have been looking intently and cannot find anything. I understand it's dependent on the application but is there any guidance out there at all?
Thanks in advance.





RE: Closure time of ESD valve
David Simpson, PE
MuleShoe Engineering
"Belief" is the acceptance of an hypotheses in the absence of data.
"Prejudice" is having an opinion not supported by the preponderance of the data.
"Knowledge" is only found through the accumulation and analysis of data.
RE: Closure time of ESD valve
Common rule of thumb for general stroke speeds mentioned elsewhere in this forum is 1 sec. per inch of valve size. That is a little on the slow side, but is generally good practice for normal autoamted on/off valves and minimize risk of water hammer. For pneumatically operated valves up to 24 inch, 1 to 5 seconds is the typical range.
RE: Closure time of ESD valve
Systems I have modelled have ESD times out to 4 minutes. Others needed high pressure nitrogen actuators to close in milliseconds. You cannot have an overriding rule for such things.
Systems may require valves to have dual cloising times. The initial time may close to 20% open very quicky and the last time to full closure may time a long time. This is typical for butterfly valves where the flow is not impacted until the valve is near closed.
It is important that that the dynamic engineering is undertaken otherwise you dont know what you dont know. Guessing doesnt go down well with judges.
“The beautiful thing about learning is that no one can take it away from you.”
---B.B. King
http://waterhammer.hopout.com.au/