Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit

Pitching tank fill and vent pipes

CLamb Member Posts: 92
I want to layout the piping for a basement Roth oil tank. Together the manufacturers instructions and the code specify that the pipe attached directly to the tank must be vertical and that all horizontal runs must be pitched towards the tank. I can't see how this can strictly be followed without using 45° elbows and running the pipes zig-zag. If there were long runs of pipe I could take advantage of its springiness and play in the threads in order to put in a slight pitch but tank installations have short runs.

Below is a diagram from the Roth installation manual. A cannot be perfectly vertical if B is pitched. C can easily be pitched from the elbow but if it then goes directly through a wall to the outside a single elbow will end result in a pipe that is atilt. Two elbows would need to used outside to get a perfectly vertical alignment.

I figure I'm just interpreting things too strictly and should just layout the pipe as best as I can. Am I right?


  • Randydaplumba
    Randydaplumba Member Posts: 4
    I've found the Roth tanks to have some movement to them when being filled. The swing joint protects the tank from those small movements. Tough installations have their compromises:[
  • Randydaplumba
    Randydaplumba Member Posts: 4
    Yes I think your right... as best you can with the conditions presented.
  • STEVEusaPA
    STEVEusaPA Member Posts: 5,322
    B doesnt have to be pitched, for the short length. C does. The other pipe is either a close nipple or a street ell.
  • icesailor
    icesailor Member Posts: 7,265
    edited January 2015
    Swing Joints and/or crooked threads.

    If you try to "cheat" in the risers, the gasket is tighter on one side and the connection might leak oil on top of the tank when filling.

    Unless you have a Ridgid 65 RC die stock and NOT a 65R TC, you can not make crooked threads.

    They want 1/4" to the foot pitch which looks like crap. But if they said 1/2" per foot, some would lay it flat. With the bubble meniscus over the line, it will drain.

    Use 2 90"s on one outlet, a 90 and a 45 on the other.

    Another thing. Be sure that you don't use Teflon Tape (Blue Monster) and Rectorseal #5 or Gasoila on the threads with tape. The tape keeps it from ever leaking, and you don't have to twist the pipe as hard to keep it from leaking and rim racking the tank connections.
  • billtwocase
    billtwocase Member Posts: 2,385
    Unless you are in a flood plain, or burying this tank in the ground, you don't need swing joints. Less connections the better on these tanks, as they are weak up top. Secure the piping to joists for strength.
  • CLamb
    CLamb Member Posts: 92
    Sounds like a lot of good advice. The Roth manual doesn't specify the amount of pitch on the fill pipe just that it be pitched. I have a Toledo 1A pipe threader which it looks like I can cut a crooked thread with. It is a receding head threader with three thumbscrews holding the pipe in place.
    Curiously, the installation instruction video linked to from the Roth website shows the installers breaking the Roth rule that "the elbow closest to tank the directs the pipe coming from the tank to a direction parallel to the wall that the fill and vent points will be located on."
  • STEVEusaPA
    STEVEusaPA Member Posts: 5,322
    Just make sure someone is in the basement watching on the first fill.