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Bent gas pipe?

brandonf
brandonf Member Posts: 205
Came across this in a friends house built in the 1920's. Never saw a soft bend on a NG pipe. Is this normal/safe?
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Comments

  • Rich_49
    Rich_49 Member Posts: 2,766
    Was performed regularly way back . Didn't you ever wonder why your Tri Stand had 3 holes with half round grooves leading out from them . Seamless gas pipe was readily available quite awhile ago , just like bending Temper copper ( BT ) . It's more than likely quite safe
    You didn't get what you didn't pay for and it will never be what you thought it would .
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  • JUGHNE
    JUGHNE Member Posts: 11,042
    Our own Muni NG system uses coated catholic protected steel pipe only for in town use. We use hydraulic benders on 1" and
    1 1/4" as a standard practice. Not done inside.
    Without the bender we would have to use 2 extra heavy duty 90 to make a riser out of the ground.
    Old school system but has the same piping from 50 years ago.
    No reportable incidents unless someone drives over a meter set.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,452
    They would go to a great amount of work to save a few fittings in the old days. It used to be common to see 1/2" copper tubing bent for water lines as well.
  • Henry
    Henry Member Posts: 998
    It is no longer permissible but common in Europe both on steel and copper.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,452
    @Henry , I would bet it is still legal with seamless pipe. Maybe with regular pipe too. They sell underground steel risers that are bent out of pipe to come up to a meter or other equipment
  • JUGHNE
    JUGHNE Member Posts: 11,042
    Our NG system uses the pre-bent 90 sweeps to transition fm plastic to steel above ground for irrigation systems in the country.
    I recall seeing in my parents house that was built in 1941-42, 1/2" galv pipe bent into offsets to avoid fittings. You had a lot more time then money in that period.
    Also to get 2" 90 ells for the main vent, pipe was cut (by hand hacksaw) at a 45 angle then rotated to be welded into a 90 configuration.

    Lead was certainly scarce in the early 40's so cement was used to seal on the oakum for cast iron hubs. Never leaked or cracked
    until I disturbed a 1 1/2" galv drain to add a fernco for extension.

    For plumbing copper I have used a lot of soft and would bend as needed. Swedge couplings in the tubing.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,452
    @JUGHNE , Yup, welded mitered pipe elbows. Not recommended due to resistance but you gotta run with what you brung.

    We removed an old boiler. When we removed the old steam header and took the insulation off. I think this was a 1937 job. Any time around WWII they couldn't get material.

    Anyhow the guy had made a 4" x 1 1/2" eccentric reducer. Took a pc of 4" pipe, cut slits in it lengthwise and folded it down to 1 1/2" and welded all the slits closed and welded a 1 1/2" half nipple on it to get a thread. Must have taken him a while. And it looked like it was all gas welded.

    As you said "a lot more time than money"
  • L Thiesen
    L Thiesen Member Posts: 54
    Years ago I was taught not to bend steel gas pipe. I believe the UPC code does not allow it but the IPC code does.
  • Leonard
    Leonard Member Posts: 903
    edited February 2018
    I was told by gas company guys gas line caps and fittings have to be stamped with G (for gas) or M ( for malleable steel), no cast iron allowed. So reading between the lines want ductile steel ,so that it bends and not cracks.

    Think I read in my text books steel can take at least ~ 30% elongation before failure. But I'ld worry about weld uniformity of seamed pipe.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,452
    @Leonard , that's why some specs call for "seemless" pipe. Most all gas codes in general do not allow cast iron fittings although there are a few minor exceptions.

    Most pipe plugs (except the smaller sizes) are usually made of cast iron. I believe in some cases cast iron flanges can usually be used. Bushings are also a no no. Have never seen fittings marked with a "G" though
  • Leonard
    Leonard Member Posts: 903
    edited February 2018
    Not sure on the G for gas, maybe it was D for Ductile iron, or W for wrought iron, or F for forged. Was long time ago, ~ 20year.

    Seems reasonable cast iron is ok for plugs, it's not going to be stressed and crack like elbows and Tees can be. In a plug the metal will be mostly in compression. In elbows can be in tension, and tensile strength of cast iron is low . Maybe 1/3 of regular everyday low carbon steel ( IE...... C1030 steel)

    Chinese restaurant tenant sold off all his cooking equipment under 30ft exhaust hood when he left. Kitchen gas pipe was ~ 3 inch main line with bunch of sawed off 1 inch pipes only closed by ball valves. Gas co insisted on a piping inspection before they would turn on gas so I could check out and fix roof HVAC . So they told me to cap off the lines, and told me about the stamping they required on the elbows and caps before they would turn on the gas.

    Turned out water leaked into old rusted utility underground steel mains, freezing water vapor made $300 gas valve on Carrier HVAC stick. I should have sent gas co the bill for that one. Gas company installed electric heat wire on their gas meters since water vapor froze to ice inside them and gas stopped flowing.
  • Henry
    Henry Member Posts: 998
    Underground riser are not covered by NFPA54 or our B149.1. They are covered by another code. Bent piping is not allowed after the meter. In Europe they bend pipe and even use silver solder copper pipe.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,452
    @Henry , bent risers are allowed. If you run polypropolyne out to a pool heater underground you have to come up with steel risers on each end and your after the meter.