gas pipe maintenance

[ER_Hopeful]

hi,

one section of the exterior gas pipe of my house(built in 1940's, in Calif)
is not under cement but under only 2, 3 inches of grass/dirt and it's got some amount of rust. I was wondering is it a good idea to bury it in cement? will this solve the problem for good or only offer little help because it's already rusted?

If not cement, what is a better solution?

thanks.

[calmloki]

Not a gasfitter, and if you blows up i don't know you.... but. When i've had to run gas pipe through concrete it has been required that the pipe have a plastic barrier betwixt it and the concrete. Don't think the concrete will help, and may increase, the amount of rusting that's going on.

[samclem]

Quote:

Originally Posted by ER_Hopeful hi, one section of the exterior gas pipe of my house(built in 1940's, in Calif) is not under cement but under only 2, 3 inches of grass/dirt and it's got some amount of rust. I was wondering is it a good idea to bury it in cement? will this solve the problem for good or only offer little help because it's already rusted? If not cement, what is a better solution? thanks.

Nope, cement won't stop the pipe from rusting, since the concrete will absorb water and hold it against the pipe (take a look at some rebar that has been in concrete for awhile--it is rusty.)

If you are willing to go to all the trouble of digging the pipe up to encase it in concrete, consider one of two other options:
- Dig a deeper trench and bury polyethylene piping that is aproved for use with natural gas (it is often yellow, flexible, and comes on a very big spool. It requires special fittings: This is a job for a plumber). The pipe will never rust, will probably never leak.

- Remove the iron pipe from underground and mount a new iron pipe above grade (usually affixed to the outside of your house with hangers). Paint the pipe with good quality epoxy paint, and it should last for many years. This is a good answer when the appearance of the new pipe won't be a problem for you. Again, this would be a job for a plumber. If you are the handy sort and can find an agreeable plumber, you could do most of the work yourself (install the hangers and iron pipe, then have a plumber come and do the hookup to the line and test everything).

- What brought this to your attention--is the gas leaking?
- I'd be surprised to learn that burying an iron pipe carrying natural gas a few inches under ground was ever within code. I'm sure it was never a good idea.
- Obviously be careful when working on this project. Turn off the gas, let the pressure out of the line, etc, etc. You can easily cause a leak and sparks when doing any excavation work. Getting blown up would seriously change your ER situation.

[ladelfina]

I think cement also has a corrosive reaction in contact w/metal, esp. in the presence of water/humidity, as in the earth. I would not want to bury a metal pipe in cement. For safety, the gas line should be buried at a depth of at least a foot or so (not sure what the current specs would be in your area of the US; here I think it's 40 cm).

We just had a gas line run and they used a somewhat rigid, multi-layer plastic-y stuff rather than metal, which I questioned, but it seems it's more resistant. They laid a bright plastic warning tape over it to alert potential, subsequent, diggers. Contact a licensed plumber/gas person.

As sam says, once you've gone to the trouble of exposing it, replacing it with sound piping at a lower level is the best bet; then you can rest easy.

[thefed]

i wouldnt bother unless theres an issue...but if you want it fixed, a plumber can run the aforementioned 'plastic' pipe THROUGH the old iron pipe to avoid more trenching



good luck

[ERD50]

Quote:

Originally Posted by samclem Getting blown up would seriously change your ER situation.

But you could support one heck of an SWR!

Seriously, gas is dangerous stuff. Make sure everything is done to code.

-ERD50

[CCdaCE]

If it's between the meter and the street, isn't it the utility companies problem?

-CC

[Goonie]

Quote:

Originally Posted by CCdaCE If it's between the meter and the street, isn't it the utility companies problem? -CC

It is in my neck of the woods. The gas company maintains everything up to and including the meter.....the home owner is responsible only for the piping on the 'house side' of the meter. Contact your gas company to find out for sure.