Terminology; Piping Plans vs. GA's 2

[pennpiper]

(A long time Piper)
From another piping forum.

The question:
"Can you please send me some sample P&ID's, Isometric drawings and G.A Drawings."

My problem with this request is in the terminology used for the last item listed. The poster (and many, many others) use the term "GA" to mean a Piping Plan Drawing. This is to me (and should be to all other experienced and dedicated "Pipers") offensive.

"General Arrangement" implies a "Sketch" type drawing representing approximately what something might look like.

This term might be more appropriate for the document we all know as a "Preliminary (or Proposal) Plot Plan." In a Preliminary Plot Plan the equipment is not accurate for size, shape or location. Therefore it is a "General Arrangement Drawing".

The word "general" (when not used to describe a Military Officer) implies:

- Not specific or definite: I could give them only a general idea of what was going on.

- Synonyms: customary, prevailing, regular, ordinary

There is nothing "General" or "Ordinary" about Piping Plan Drawings. They are very special and very specific to their intended purpose. They are also very detailed in the level of information presented and in dimensional accuracy.

I hope that someday people everywhere will discontinue their use of this offensive term for the important document truly known as a "Piping Plan Drawing."
__________________
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[rmw]

Not knowing the specifics of your case, the question doesn't seem out of line to me. I work with P&ID's which show all the components in the piping; from the piping to all the widgets that are attached or connected or in line and GA's that show the location of the components to which the piping is connected and then individual piping assemblies and piping spools as a subset of that.

The GA's I use are not sketches, but very detailed drawings from which the piping, whatever it ends up being, is determined.

And, all of the above are done in 3D with Isometrics.

So unless your situation is pure piping and doesn't include any of the ancillary equipment I mentioned above, I don't understand your issue.

rmw

 

[JLSeagull]

General arrangement drawings depict the physical layout of equipment packages.

 

[BigInch]

I think the problem was somebody was calling the piping plan drawings by the name general arrangement dwgs.

**********************
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[pennpiper]

"Big Inch" understood the issue.

 

[katmar]

Perhaps this terminology varies geographically? Certainly here in South Africa the term "piping general arrangement" is commonly used, so I would go along with rmw's view.

I have always understood the word general to have basically the same meaning, whether you talk of a general officer, or a general manager, or a general factotum. As pennpiper said, it means "not specific" - but I would take its meaning to be closer to "all encompassing" or "not limited" just as the general officer has a blanket responsibility for the army, the general manager has an overall responsibility for the business, and the general factotum is responsible for all the crappy jobs.

To me, any drawing with the word "plan" in it means a view from above, whereas a GA will include elevations and sectional views as well. I would regard a "view from above" drawing of pipe rack layouts, or tank farm layouts, as a "Piping Plan Drawing".

I have NEVER thought of a piping GA as a sketch. They are very detailed, very well thought out (hopefully) and very well drawn.

But then, my involvement with piping has only been from either an hydraulics design point of view, or as a project manager getting the designs done and the piping erected. Never as a "piper". So if the pipers really feel offended by the terminology "GA", I will do my best to avoid it in future.

Katmar Software
Engineering & Risk Analysis Software

http://katmarsoftware.com

 

[stanier]

There is also an industry bias to go with the location in the world. Not everyone works in petrochem and all manner of terms are used from power gen., water & waste water, oil & gas, food, pharmaceutical, pulp & paper, mech services etc etc. The latter does not even know what a P&ID is!!!

We even have government departments confused between what constitutes piping and what is plumbing. A recent Queensland government report referred to the failed plumbing in an SWRO plant. The piping was class 600 DN 1000 and in UNS 32750 (super duplex stainless steel).

I would not lose sleep over it. If the people paying the bills want to call them "those sketchy things with squiglly lines on them", take their money and run.

 

[pennpiper]

Stanier
Good input, thank you.

 

[C2it]

My thoughts ... In petrochem prior to 3D CAD, piping GA's (pga's) were the primary source of geometrical data, created by experienced piping designers. Isometrics etc were then created from those drawings and the whole lot would go to site.

In these days of CAD, piping designers create the model. However it is common for the cost of pga's to be avoided entirely, even though they can be simply created from CAD software. Instead iso's and mto's come from Isogen software and the model (on a PC) goes to site. There it's quite inspirational to see rufty tufty pipe fitters, busy with a PC and mouse, checking out a pipe route to the nearest millimetre.

 

[Gator]

There is nothing "General" or "Ordinary" about Piping Plan Drawings.

I agree.

But, for what it's worth, I, too have seen the term 'General Arrangements' used to describe piping plans/elevations/sections. This after almost 30 years as a piping designer/checker, having worked in upstream and midstream oil, chemical, metals processing (hydrometallurgy), pulp and paper and industrial gases.

Paul