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Traps, Trap Arms & Fixture Arms illustrated

Posted by lazypup ( on
Sat, Jun 23, 12 at 2:48

Quite often when we are discussing traps, trap arms & fixture arms on the forum I see a lot of contention which results from a basic understanding of the proper "Plumbing Terminology". I decided to make up the attached illustration in the hope that it might help ppl understand the code better.

Although this cannot address all the issues or rules in regards to traps, trap arms & fixture arms I feel it should present enough basics to help us work out the details.

You may want to copy and save this illustration for future reference.


Follow-Up Postings:

RE: Traps, Trap Arms & Fixture Arms illustrated

Nice illustration!

RE: Traps, Trap Arms & Fixture Arms illustrated

more details:
The sink drain has a tailpiece too.
Be aware that the word can apply to two different pieces of tubular.

The unvented part is the arm.
Unvented pipe known as "arm" is subject to Distance limits shown above.
This unvented pipe must be horizontal, with the slight slope shown.
It cannot run downhill faster than that. It cannot be flat.
Therefore, it must run horizontal-with-slight-slope over to a vent.

The trap is always illustrated directly underneath the sink drain.
It is not required to be there. It can be elsewhere. This is first-level F.Y.I.

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