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Maximum pitch on steam mains?

I know there's a minimum pitch on mains, but is there a maximum pitch beyond which it's best to just use a vertical drop?
Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.


    EBEBRATT-Ed Member Posts: 15,511
    There is no maximum.

    Below the minimum pitch water condensate will be trapped in the pipe. Any pitch exceeding that is fine.

    There are different pitches for parallel flow (condensate flowing with the steam) and counter flow (condensate flowing against the steam)

    The amount of steam and condensate a given pipe can handle (the connected steam load) depends on pipe size and pitch.

    For example:

    2 " pipe with the standard 1/4" /foot parallel flow pitch will handle a certain steam load. If installed vertically (maximum pitch) it will handle a much bigger load
  • KC_Jones
    KC_Jones Member Posts: 5,736
    As far as I know there isn't a maximum, but others with more experience will comment, but I can see the potential for problems.

    The issue is primarily staying well above or below the boiler water line. Excessive pitch would most likely lead to part of a main approaching the water line which has the potential to cause issues, not definitely just a potential.

    I actually rerouted one of my return pipes as it gradually sloped through the boilers water line and would cause noises on occasion. So I decreased the slope to keep it "dry" and then had the vertical drop near the boiler.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • delcrossv
    delcrossv Member Posts: 742
    edited December 2021
    @KC_Jones Nope. It's splitting a longer main so everything is well above the WL. Ends stay where they are.:smile:
    Trying to squeeze the best out of a Weil-McLain JB-5 running a 1912 1 pipe system.
  • boblozeau
    boblozeau Member Posts: 2
    Good afternoon,
    What always worked great for our Mechanics and HVAC/R Techs. was to put our magnetic torpedo levels on the horizontal runs to just break the bubble and pitch the steam supply towards the heating coil, and pitch the condensate return away from the heating coil, and towards the condensate return pump. This method was easy and it worked with great success where we completed thousands of feet of commercial low pressure steam sch80 piping installations, from 1/2" drip legs, to 4" steam mains and condensate returns, with no water hammer and no knocking.
    I hope this helps someone.