Trap Arm Restrictions

[ME27272727]

I'm looking for any code reference to limitations on change in direction of trap arm before connection to vent, as well as whether or not two or more traps may be joined to the same trap arm (separate, parallel connections, not in series). Thank you.

 

[dbill74]

Not aware of limitations regarding the number of changes in direction except with respect to cleanouts.

IPC and UPC have chapters dedicated to vents and what is required and prohibited when it comes to venting fixture traps. I suggest careful reading through the code you use most. To better answer your question we will need more information about the setup you are looking at, there are too many variables/options to provide meaningful advise with the information given.

 

[PEDARRIN2]

IPC 1002 allows for maximum distance requirements between the trap and the vent. I would recommend any changes in direction be with fittings less than 90 degrees, but if required, I would assume a cleanout will be required.

Although a different approach, you could argue connecting the trapped fixtures as you describe would comply with some of the wet vent sections, like combination drain and vent. Refer to some of those requirements to see if your situation can fit into one of them.

 

[ME27272727]

Thank you. I think I found the answer I was looking for after researching the purpose of trap arm max distances. The application was in a combination waste and vent system under the 2009 NSPC, and was curious as to when a section of piping was defined as trap arm and when it was combination waste and vent section in the rare setting that I described above.