There are all kinds of engineering drawings, used for all kinds of purposes:

• Pipe fitters and millwrights use Plan & Elevation drawings to make sure fluid system flanges, elbows, tees, etc., line up with each other, and don’t run into anything.
• Exploded view drawings help maintenance folks identify parts, and, when they need replaced, make sure the new ones go in the same way the old ones came out.
• Fabrication and machining drawings (usually to scale) are used to ensure the part being made is the right size & shape, that mounting holes are in the right place, and that critical surfaces are as flat & smooth as they need to be.
• Then there’s the Piping & Instrumentation Diagram (P&ID)…it depicts an overall view of a system, showing the flow (usually fluid or electricity) through that system’s components, giving the viewer an understanding of the operation, and expected results from said operation.  It should not be confused with its simpler cousin, the flow chart that is so dreaded by OTE-types (“Other Than Engineer”…you know who you are,) of which these are my favorite examples:

The big difference between a flow chart and a P&ID is the symbols.  In fact, you can find ISO & ANSI standard symbols for many components you’ll find in fluid & electrical P&ID’s.  Some examples of symbols you might find in a compressed air system are:

Compressors:

Air preparation & handling:

Instrumentation and control:

Occasionally, we’re asked if there are standard ANSI or ISO symbols for any of our  engineered Intelligent Compressed Air Products…and there aren’t.  Perhaps one day they might make the cut, but for now, their standard convention is to choose a shape (user preference…you’re the one it’s gotta make sense to) and call it out by name.  It might look something like this:

Oh, and if you’ve ever got any questions about your compressed air system that you think looking at a drawing together could help us solve, you can send that drawing to us at techelp@exair.com, and one of us will be happy to help.