Gas-Black Pipe

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we ran some CSST through a crawl space to supply fire place log lighters. We transitioned to black below the floor for the connection to the valve and lighter bar. Months later we went back on a service call. The crawl space was loaded with gas smell!

After airing out we discovered the rock masons had used acid cleaners on the fireplace rock work. Some of this dripped on the exposed CSST near the transition fitting. In several months it had eaten a pin hole in the CSST.

Dodged a bullet on that one !!

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Bill_3

Black-pipe

Why do they use Black pipe on a gas line. Could you use Galvanize pipe.

Jacob Myron_5

Gas Pipe

In the old days when the choices for piping systems was limited black steel pipe was the most economical pipe to install for gas lines.

Galvanized pipe could have been used. Originally gas came in many different types, ie. coal gas, illuminating gas, natural gas and blends of each type. The gas had a high contentent of moisture. It was thought by most the if galvanized pipe was used the galvanizing would flake off and added to the normal amount of dirt and pipe scale that would drop off the vertical piping a stoppage could occuur at the base of the riser.

basically it was more economics than science that caused black pipe to be used.
Jake

Dale

Jakes right

At the beginning it was the cheapest thing that worked and some of the wet gas near the wells had sulfur and other contaminants that would flake the galvanized off and clog up orifices. I much prefer galvanized outdoors since no paint and no rust. The gas companies along the ocean find the black pipe doesn't last long with salt spray.

tombig

Black Pipe

Are you teling me that the zinc relly DOESN"T flake off? Where I'm at if an inspector saw a pice of galv. behind 20 fittings he'd make you change it out! And to think......all these years.....and galvanized pipe really doesn't flake......Hmmmmm

Unknown

Galvanized still flakes

and here in RI the gas company does not allow it on natural gas systems. I have found also that it tends to have sand holes in some of the fittings.

Same problem with copper tubing used on pilot tubing when heated at the pilot connection you get black flakes in the orifice. Only use aluminum or steel tubing on gas pilots.

hr

Galvanized

is allowed in the NFPA 54 code if it meets ASTM A 53.

Used to be a time when copper, brass, and galv were not allowed due to the hydrogen sulfide, I've heard. "All natural gas that is distributed in pipelines, and all LP gas, in the United States is treated to remove sulfide." NFPA 54 1999 issue. If the gas is obtained directly from a gas wells it may be more of an issue. (more than 0.3 grains of hydrogen sulfide per 100scf of gas)

I too, work in an area where the inspectors frown on galv in natural gas piping. Hard to argue with city hall Local AHJ can modify or add language to the codes, I've found. Gets to be a hassle sometimes!

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Dale W.

Black pipe with galv.fittings

This is how all the gas piping was done in our area and the way I learned to pipe gas. We were told galvanized pipe flaked so it could not be used. I don't know why they let the galv. fittings in the line.

Speaking of gas piping...
I was called in to repair a piece of CSST tubing in a house a few months ago. The CSST was installed by a licensed mechanical contractor. When he attached his fittings to the CSST he stripped the plastic covering back about 6" from the fitting. A carpenter was tearing out a wall and removed a hot wire from an electric box. The wire swung down and hit the CSST and blew a hole through the pipe. Fortunately it didn't ignite.

I know one of the manufacturers requires the plastic to be up inside the heavy brass fitting. Another allows the thin CSST to be exposed. After seeing what happened at the above job, I feel there should be no exposed paper thin CSST.

If that hot wire hit the plastic it would not have arched.

Well, sorry for getting off the subject, but thought I would relate.

Dale W.

Unknown

Guys from down near

the wells tell me that their gas is as they call it real dirty. They find all kinds of stuff in drips and sediment traps. It also sometimes gets into gas valves. I wonder what the hydrogen sulfide levels are in that gas.

Up here in RI we have some real old mains and underground piping systems. Some of the stuff that is lying around in those pipes is really corrosive. They also have found some PCB's in the old compressors we used to use. All of that raises havoc with galvanized and copper piping.

Glen

ASTM 53

If your code south of the 49th is the same - the A53 allows "pipe, steel, black and hot dipped, zinc coated welded and seamless". I have worked both sweet and sour gas - and have seen enough to spec only black A53 or A106B on any gas job. Outdoor installed piping is required to be painted regardless - so if you have to paint - why raise costs by installing galvanized? In B.C. we're allowed up to 66psi in an industrial setting - even there - it's not enough to scrub off the galvanizing - but I'm still very suspicious of the sulphur content. Just east is one of the largest sulphur scrubbing plants around - handling both Alberta and northern B.C. gas - most of which ends up in northern California. It's the cleanest product available - but stick with black pipe and fittings. And to think the Chinese invented this business by piping coal gas through bamboo!!!
Cheers

Dale

CSST

Funny how people think stainless won't corrode. I remember early lennox pulse connectors with pin holes because leak soap with clorine was used as a bubble check. We had an attic leak with CSST when lightning hit the house and the CSST near an attic sheet metal air supply had a hole blasted into it. I think bonding wasn't done on the sheet metal. Funny business