Gas Line Question

I'm surprised that someone would use threaded couplings undreground. Underground flammable gas line couplings should be compression type couplings that eliminate weak spots caused by cutting threads. The whole line must also be coated or taped to prevent corrosion. Most undreground lines now are non-metalic.

"I'm surprised that ....."

I agree with you rickwil in your surprising for using threaded couplings in a buried/underground gas line. I'm not only surprised, but I'm astonished.

I believe that kind of installation would be illegal in most jurisdictions.

HDPE should have been used instead of metallic, coated or not.

I would inform the Licensing or Inspection Board in your area

qaqc, here's an ancillary question. Although plastic is de rigueur for ground-imbedded gas lines, it is not used above ground (say, in basement or crawlspace runs...where black pipe remains standard). My question: how is the transition done properly from HPDE to iron? And at what grade level: below ground? at grade? or above? Is the interface fittingh a compression or threaded coupling or something else? Links and or pic will be helpful and appreciated?

Thanks.

HI (happenstance interloper)

PS: Oh yes...justification or need to know? Well, a car ran into our 300+gal LPG tank, bending the up line from the house. Gas company says to replace the line to the house (because of bend and because of age (of once-acceptable iron pipe)...before red tag can be removed to allow tank refills. They will remove iron and then provide the new line only after the old pipe is excavated and exposed.

Thank very much, qaqc, the pic and link were exactly what I was hoping for. The only difference in my installation would be the regulator's location: on the supply down line from the tank, upstream of the metal-to-plastic/underground/plastic-to-metal transition before riser pipe entry at the house wall. Although I'll have plenty of digging to do, I think it best to leave the plastic-steel pipe junctions (and liability) to my LPG vendor...as these junctions seem to be the major cause of service (and trunk) line failures...some catastrophic. A recent, holiday incident that was in the news round here will attest to criticality of line joints and the potential devastation from failed gas lines:

xmas Rancho Cordova incident

Who or what was to blame?

slide show

Thanks and I hope it works out well.

I have some horrid pics of bad installations that I use in a HSE presentation on some of the gigs I supervise.

In fact, I am building the file and the links are greatly appreciated.

Safety is the #1 Priority for any project we undertake.

I also had water in 1" BIP underground line 2 yrs after install. Blew out about 1-2 Lit water from 40 ft of pipe (~15% volume), then could not hold pressure. Excavated and found hole in threads. Excavated rest of line, found numerous damage to yellow BIP coating where a clamp or wrench were used - with no subsequent protection. Contractor is not yet cooperative, and may not be. Locally, threads are OK if tar coated and wrapped. Can't tell if tar was used, but wrapping is minimal (2 layers at best). Rust evident all over the place.

How can I tell if the tar was used? Should there be a visible residue after removing the tape? (Trying to nail it down for leverage on the contractor)

Tks, Homeowner

Call the Gas Company so that they can undertake this job. It is their job to tackle the contractor.

But, of course, dig up the line first if it's not already.... Gas companies will not help in that regard; and you wouldn't want to pay their $hourly even if they would...which they won't.

Great call, what astounds me about a weak economy is the fact that everyone who has been laid off becomes a "contractor" and takes on jobs much cheaper than anyone else.

Already, I could start a business fixing what was done improperly and cheaply in residential, commercial, and industrial projects (especially the small ones).

It is always a good thing to remember, that if it sounds like a great deal (especially in economic downturns), it will often turn out to be a horrible fiasco.

I have seen it happen everytime and soon I will be offered slightly used equipment by the new "contractors" who have failed, as in the past.

Bless the person who has the skills and nohow who are strating up right now, they deserve the break, but check, check, check.

Anyone want to join me in Pipeman's new venture of making bad projects right?

Do what you have to do to replace your line with SDR 11 (or better) Driscopipe HDPE (High Density PolyEthylene) tubing, anodeless risers, & compression fittings. One manufacturer of the risers is RWLyall Co.

It will. You didn't mention the black pipe size but, assuming it is large enough, the classic repair is to feed a smaller plastic line inside the black pipe and make the end connections to the plastic; thereby replacing the black pipe line.