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Which copper tubing

rgar98 Member Posts: 59
I'm replacing an indoor tank to oil burner line in Maryland. Is Type M tubing adequate?


  • Intplm.
    Intplm. Member Posts: 1,619
    Commonly used tubing is soft coiled 3/8 O.D. type -L- copper tubing. I've never used type -M- for an oil burner.
    Is it adequate? you ask? Probably, but why use type -M- ? Are you in abundance of -M- tubing and wanting to use it up?

    I have seen hard copper tubing used commercially to supply oil to burners. Soldered and fit as if it were water piping. Was surprised to find it installed for this use. Not my choice. Not the best workmanship.

  • Jellis
    Jellis Member Posts: 228
    According to NFPA 31
    min .032 wall thickness copper tube or thicker may be used. which would mean type M is too thin.

  • STEVEusaPA
    STEVEusaPA Member Posts: 6,386
    You can't use M. It's not going to flare properly, and you absolutely can't solder oil lines.
    And it needs to be done by code, for safety and liability. Specifically jacketed, and/or OSV, firomatics, etc.
  • rgar98
    rgar98 Member Posts: 59
    "Are you in abundance of -M- tubing and wanting to use it up?"

    How'd you know? I have a coil of 3/8" type M that I used to cool beer (at the initial stage of the brewing process).
    Does type L bend easily with those hand-held spring devices?

  • rgar98
    rgar98 Member Posts: 59
    edited September 2020
    Thank you for the info. I appreciate it.