Running trap

[SNations]

I have heard that a "running trap" wasn't allowed, but when I tried to look up a code citation I couldn't find anything.  About all it says is that traps shall be of a standard design, which is a rather nebulous term.  Can anybody shed light on the concept of a running trap?  Is it allowed by code?  Not allowed by practice?  Anything?  Thanks

[Marc]

Running trap

The only application for 'running' trap that I've ever heard is on the condensate drain line for the indoor section of a split-style AC system. I don't recall it being used in plumbing.

Edited September 15, 2021 by Marc

[Bill Kibbel]

I don't think you'll find anything using that phrase.

The applicable code reference should be in a section somewhere below the list of prohibited trap designs.  It states the maximum horizontal distance allowed between the fixture outlet and trap inlet.  In the adopted codes in my area, the max is 30".  

[Jim Katen]

9 hours ago, SNations said:

I have heard that a "running trap" wasn't allowed, but when I tried to look up a code citation I couldn't find anything.  About all it says is that traps shall be of a standard design, which is a rather nebulous term.  Can anybody shed light on the concept of a running trap?  Is it allowed by code?  Not allowed by practice?  Anything?  Thanks

I can't find a definition either, which is surprising. My understanding is that it's a trap that has horizontal inlet and outlet openings at roughly the same level, and that doesn't serve any particular fixture. When I used to live back east, I saw them frequently in the form of "whole house" or "sewer" traps. I've never seen that application on the west coast. 

The "standard design" requirement prohibits people from making up their own traps from spare parts. It works hand-in-hand with the requirements that the trap be listed or labeled and that it be stamped or marked with the manufacturer's name. 

The IRC simply prohibits building traps (perhaps that's where the "running traps aren't allowed" thing came from), while UPC (1008) says that building traps are prohibited unless required by the AHJ, then it goes on to give specific requirements for installing them.  

In practice, the only times when I see problems with running traps is at bathtubs or showers, when someone places the traps several feet away from the drain outlets. 

[SNations]

Thanks guys.  Bill, so in answer to my question it seems that there's no prohibition for a running trap, only a restriction on its location just like all traps.   

And Jim, I don't see any requirement that a trap be listed or labeled.  At least not in the IRC.  Is that a UPC thing?

[Jim Katen]

36 minutes ago, SNations said:

And Jim, I don't see any requirement that a trap be listed or labeled.  At least not in the IRC.  Is that a UPC thing?

2609.1 ? 

[Jim Baird]

So called "master traps" are paired with grease traps for commercial kitchen use.  Grease trapping is a local sewer issue.