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Heating Pipe Identification

AlexPetron Member Posts: 22
Hello Everybody!

Please help me to identify these black pipes. Six of them, except for the one in the middle, measure 9½ feet long with a 3 inch diameter. The middle pipe measures about 10 feet long with a 2½ inch diameter. They were intended to be used for piping a new gas heating system. Would these be galvanized? Are they Steel or Iron? Thank you for the assistance.


  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,578
    Are these pipes intended to be used for the gas supply, and what type of heating system is it-forced air, hot water, one pipe steam, or two pipe steam? Generally, galvanized pipe is not to be used for a gas supply pipe.—NBC
  • hot_rod
    hot_rod Member Posts: 22,256
    There should be labeling on the pipe somewhere. It would indicate scheduled, listings, typically a manufacturers name also.

    Most of it looks like "plain end" which could be welded or grooved, or threaded to connect.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • GroundUp
    GroundUp Member Posts: 1,926
    edited January 2019
    Are those ID or OD measurements? The smaller one looks like schedule 40 carbon steel while the other 6 look like cast iron waste and vent piping, but none of them would measure 2.5" or 3" OD. Definitely do not look galvanized, but it may be an optical illusion. There are no markings anywhere on any of them? Galvanized is very common for gas piping here in MN, but only in threaded sizes 2" and under. Why are you wanting to figure out what it is?