Undersink Plumbing Questions

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by perion, Sep 24, 2020.

  1. perion

    perion New Member

    Apr 17, 2019
    Southern California
    I'm redoing some plumbing for a kitchen sink, and have a few miscellaneous questions.

    - I've seen the terms "trap arm", "wall bend" and "wall tube" used to describe what I believe is the same part (i.e., the tubular pipe that connects to the J-Bend on one end and the ABS waste pipe at the other). Are these the same part?

    In order to continue, I'll refer to the part I've described as the wall tube.

    - There's a 2" ABS waste pipe in the wall, and I need to attach a 1/4 bend (90 degree) fitting to it. Can I use a standard 1/4 bend fitting, or is it best to use a long sweep one?

    - The wall tube (which came with the P-Trap kit) has a beveled flange and a length of 7.5". I'd prefer one that's ~12", but haven't any luck finding one online. Does such a beast exist; if not, is there another way to do this without using a coupler?

    Thanks ... and if you any questions about what I'm doing (I know I do), please feel free to ask.

  2. breplum

    breplum Member

    Oct 2, 2004
    Plumbing and heating contractor
    San Francisco Bay Area
    In the horizontal plane, a long sweep is required for all waste piping.
    A trap arm is the branch from the tee to the trap, and I suppose wall tube is the arm section of a p trap.
    In chrome, there are lots of long wall tubes. I've got three 18 inch ones on my shelves. Plumbing parts stores have them.
    I recommend plastic tubular p traps.
    Slip joint couplings are not allowed on the end of a p trap. Off your ABS pipe extension, you can stub out with pipe to meet the p trap.
  3. Sponsor

    Sponsor Paid Advertisement

  4. perion

    perion New Member

    Apr 17, 2019
    Southern California
    Thanks for the response ... it was very helpful!

    I plan on using a plastic tubular p-trap, which is why I was looking for a longish plastic (polypropylene) wall tube with the a beveled end. I didn't stumble across any of those online ... but I did find some which are listed as direct connect. Just out of curiosity, are those okay? Regardless, your suggestion of stubbing out to meet the p-trap sounds like the way to go.

    Once again, thanks.
Similar Threads: Undersink Plumbing
Forum Title Date
Plumbing Forum, Professional & DIY Advice Is this undersink plumbing to code? Apr 16, 2016
Plumbing Forum, Professional & DIY Advice CPVC MIP threads compatible with FIP flexible metal faucet line? (installing undersink water filter) Jun 6, 2021
Plumbing Forum, Professional & DIY Advice Undersink shutoff valves locked up solid...need advice Oct 13, 2020
Plumbing Forum, Professional & DIY Advice Undersink water filtration question Apr 27, 2019
Plumbing Forum, Professional & DIY Advice Two Basement Sink Install w/undersink pump - venting Nov 28, 2015

Share This Page