6 replies to this topic

[Moh.Abdelhameed]

Hello,

Is there a clear statement in the API or ASME that states "No manual isolation valves or restrictions shall be installed between single relief device and the protected vessel".

 

If yes, please specify the standard title (Ex: API-521) and page number. Also, a screenshot would be helpful.

 

Thanks in advance.

[breizh]

Hi,

To support your work , consider these documents attached Leser on page 6-3-7 and extract of API 520 part 2 

 

note : it's your decision at the end of the day .

 

 

Good luck 

Breizh

[fallah]

 

Is there a clear statement in the API or ASME that states "No manual isolation valves or restrictions shall be installed between single relief device and the protected vessel".

 

Yes, there is a statement in ASME Sec. VIII Div. 1, refer to what you mentioned; but with exceptions such as using appendix M in that ASME Code...

 

[latexman]

Did you read API 520, Part II, 7th Ed., Section 8, "PRD Isolation (Stop) Valves", pages 25-35?  There's lots of good information and drawings there.

[Bobby Strain]

API or ASME is not necessarily what determines the isolation valves outside the USA. And it appears that you are not located in the US.

 

Bobby

[Bitan729]

I have seen one of the Air separation EPC companyfollow this philosophy, even with high pressure liquid oxygen storage. But from operation point of view it is always better to have two PSV with individual isolation valves for each of them, so that they can be sent to calibration from time to time.

[seuenergy]

I think there is no mandatory requirement from codes or standards from regulatory. These are defined in company's engineering and operation philosophy.