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Orientation of T&P valve

Sethamin Member Posts: 58
So I'm going to add a skim port to my steam boiler. I was going to tee off the nipple that's currently being used for my T&P valve, seen here:

My question is: why did someone add the elbow so that my T&P is facing "up"? Is there something special about the orientation of a T&P valve on a steam boiler? Can I just make the T&P valve elbow straight down and attach the discharge pipe directly to it?

(And before anyone points it out: I realize the discharge pipe is both too short and not supposed to be in black pipe. I plan on replacing it with a longer piece of copper)


    EBEBRATT-Ed Member Posts: 13,087
    The ASME Boiler code requires all relief valves (water boilers) and safety valves (steam boilers be mounted "stem up"

    You can replace the elbow with a tee and just remount the valve in the same position.

    I believe they do this to try and prevent sediment etc from settling in the valve seat

    By the way the relief valves and safety valves open on high pressure. Nothing to do with temperature. A T & P valve is on a water heater, and they can be mounted stem horizontal
    STEVEusaPAZmanLong Beach Ed
  • Sethamin
    Sethamin Member Posts: 58
    edited August 2022
    Thanks, that's just the info I was looking for. It appears that this is wise, too, because when I removed the fittings both the nipple and elbow were completely full of sediment.