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Pipe pitch-one pipe steam

Brad White
Brad White Member Posts: 2,398
Hi Glen-

Swing joints are one way to handle this. I would not force the piping beyond the most gentle persuasion. Remember that any force you impart on a pipe will show up elsewhere in the system and you may not like the result... :I

Picture leaving the main with a nipple 45 degrees from horizontal (as an ideal). A 90 elbow on that nipple would bring the direction back to parallel with the main. A street elbow or better yet a 6 to 12-inch nipple and another 90 will allow you to again be perpendicular to the main but allow a specific pitch. A union can also be a way to adjust then "lock" the pitch to the correct degree.

I prefer longer secondary nipples to absorb some of the thermal stresses. Picture the expansion on the piping in your mind's eye as it heats up. Think "springy".
"If you do not know the answer, say, "I do not know the answer", and you will be correct!"

-Ernie White, my Dad


  • Glen_7
    Glen_7 Member Posts: 82

    I have a one pipe steam system and would like to add a radiator to an unheated storage room. I already have a tap off the main available. My question is when running the pipe, I know it needs to pitch back from the radiator valve to the main. Since elbows are 90 degrees, how does one accomplish a pitch? Swing joints? A look at my current piping doesn't seem to incorporate them. Does the black pipe just allow it to be "persuaded" to pitch?
  • Glen_7
    Glen_7 Member Posts: 82


    As always, thanks for the response. One last thing, when I am at the point where I want to attach the short riser to go through the floor into the valve, and the pipe is of course pitched at that point, do I use just one elbow or is the pitch noticeable enough at that point that I need the swing joint there as well.
  • Tom Hopkins
    Tom Hopkins Member Posts: 552

    You need swing joints wherever a horizontal run connect to a riser.

    The risers should be completely vertical. The last one feeds into the bottom of the angle radiator valve.

    You can put wooden checkers under the far legs of the radiator to give it pitch to the riser, and the pipe can handle that much twist with no problem -- no swing joint necessary.

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