P&ID Rules about Flanges
P&ID Rules about Flanges
(OP)
Don't know if this is correct forum to ask....
Are there rules about which flanges need to be shown on a P&ID (EFD, MFD)? I usually have only included flanges when they are:
1) First flange off of a piece of equipment
2) Blinding points
3) Flanged valves
The question came up when I was getting some drawings updated on a run of flanged piping. Flanges every 20 ft. or so with no point except ease of installation. Do I need to include these on a P&ID?
Thanks in advance.
Are there rules about which flanges need to be shown on a P&ID (EFD, MFD)? I usually have only included flanges when they are:
1) First flange off of a piece of equipment
2) Blinding points
3) Flanged valves
The question came up when I was getting some drawings updated on a run of flanged piping. Flanges every 20 ft. or so with no point except ease of installation. Do I need to include these on a P&ID?
Thanks in advance.





RE: P&ID Rules about Flanges
RE: P&ID Rules about Flanges
On a occation a break spool could be marked - but as you may agree your own rules are more like a guideline
Best regards
Morten
RE: P&ID Rules about Flanges
RE: P&ID Rules about Flanges
Zelgar
RE: P&ID Rules about Flanges
If the P&ID set is in addition to a piping layout drawing (eg isometric drawing), then often time, for clarity, only first flange off of equipment and major interest flanges are included on the P&ID.
I always show instrumentation flanges (including valves). Otherwise, people assume they are threaded. Then again, they may be welded, so I also show sock welds.
If the P&ID is it, without piping drawings, then "all" the flanges are shown - since no other drawing will indicate them. This is typical for small sites, such as a single well tie-in, LACT units, etc.
"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
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RE: P&ID Rules about Flanges
RE: P&ID Rules about Flanges
zelgar - Good point that you made. I have already discussed with our FUGEM coordinator to verify that he does not need the flanges shown for monitoring. We do not have requirement to sniff flanged connections in our location. Yet. Hmm. Also no environmental regs or permits require us to identify flanged connections on this system.
Ashereng - We have iso's that cover this line (Class 2) and I have already updated them with the detailed installed components. Thanks for thinking of this, but this time I had thought of this myself. Point for me.
Our company has adopted the PIP for Documentation Criteria as well, and there is no mention either way of the treatment of flanges. I am now convinced that my rules work for our location, and more importantly, that they work for applicable codes and standards. Thanks for all of the help.
RE: P&ID Rules about Flanges
"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?
RE: P&ID Rules about Flanges
With regards to showing flanges on instrument my experience is that practise varies from company / site to company/site
I prefer not to show them but to include a "typical diagram" in the legend. This typical can show all the hookup vales, drain/vent etc.
Should an instrument diviate from the standard (or be a type thats rare and dont have a "typical") then show everything.
Best regards
Morten
RE: P&ID Rules about Flanges
My own preference is to minimize flanges on P&IDs except as needed to clarify the design (orifice flanges, where you have a spectacle blind, etc). This topic could likely generate heated discussions over what is 'right'.
RE: P&ID Rules about Flanges
"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
Have you read FAQ731-376 to make the best use of Eng-Tips Forums?