P&ID Standards

[Procman]

We have developed a standard at our company for P&IDs using ISO, ANSI/ISA and the SSG (Pulp & Paper) standards as a basis. I receveived a couple of comments regarding OPC's:

On the off-page connector arrows for primary and secondary lines, do you say "From pump no....." or "From tank no......." I find the description normally indicates from which pump it is coming, but not necessary from which tank/chest. Eg 300 kPa Service water is from the 300 kPa Service water pump and 3000 kPa Shower water is from the 3000 kPa Shower water pump. It doesn't say from the Warm water chest or from the Polished Backwater chest for example. I prefer to use the tank number instead of the pump number as it gives more information. In this case the name is even more sensible than the equipment number.

If you have a line not going to a specific piece of equipment, say dilution water that goes to all the stock chests, what do you use for the "TO..." The description is Dilution water header, but it is going everywhere.

When you have a line like shower water running over several P&ID's, do you use the same "FROM..." and "TO..." off-page connector arrows on all the drawings that it crosses, instead of: From polished water chest, to Wet end showers; From wet end showers, to Press showers etc? Our current drawings are like this using drawing heading and is very confusing.

Please comment.

 

[saxon]

Procman, In the interest of saving drafting hours and ease of making revisions; I prefer the simple, "From Dwg. xyz" or "To Dwg. zyx" (both based on direction of flow). When tied to a specfic Equip. No., when revisions come down the line over the years,which they will, it makes revising the continuations tedious and difficult.

saxon

 

[psafety]

Procman,
We typically come from/go to next piece of equipment pump/chest etc. and yes Dilution Water Header, but our continuation blocks also reference the coordinate (horizontal/vertical grid reference) of the connection point.

 

[jsummerfield]

My project has HVAC Duct and Instrument Diagrams. The arrows include the drawing number in the to/from format with a sequence number that is the same at both ends. Also, the pipe line number and process code is useful for identifying specific line detail.

John

 

[OilBoiler]

We label the connector arrows with the drawing number, a specific letter for that stream, and an additional comment to where the stream is going and/or the stream name. For instance, if you have waste water going from pump #1234 and to Pump #5678 and it also goes to drawing #23. A letter or two letters would be assigned to this stream. We would have the connecting arrow indicating that the stream "AB" is going to drawing #23 "to Pump #5678" and with a comment that says that indicates the type of fluid, in this case "wastewater".

That is usually a very good and useful way to label. It makes it easier when tracing lines down.