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Well, I was going through some required specifications for my project, and I came across the following :
"fittings for black steel pipes 50 mm diameter and under and for all galvanized pipes to be screwed malleable iron, 1030 kPa steam working pressure rating, banded type. "
I have two questions:
1- The pipes being specified for water or air, what does "steam working pressure" mean?
2- what does "banded" mean ?
Thx,
Paul
"steam working pressure" is basically a pressure rating assigned to steel and iron pipes that may be used in a steam conveyance system.Quote:
1- The pipes being specified for water or air, what does "steam working pressure" mean?
2- what does "banded" mean?
"Banded" is best described by the first photo.
They have a band cast into the fitting at the point where the fitting is threaded.
The photo of the 90 is of the unbanded type.
Thanks growler, you've been a tremendous help.
So basically, all the threaded part of the fitting will be banded from the outside ?
Paul
Correct.Quote:
Originally Posted by coolpj
An unreinforced fitting has the potential to crack or to develop hairline cracks while being tightened.
Black iron is for gas
Thanks again growler.
doug238, indeed black steel is specified for gas piping. However, there is a growing trend to adopt copper pipes for indoor installation.
But I would assume that the outdoor underground main pipes would still be specified as black steel.
Black iron is basically unprotected. Underground you would use galvanized. Black iron will rust.
I take your point.
Can black steel be used underground if it is painted with anti-corrosive paint and wrapped with 3M?
Even the galvanized steel underground pipes still need to be wrapped with a special protective tape (like 3M).
Coz if the pipe is subjected to serious scratches, the coating would be removed at some point, leaving the pipe exposed to rust at that particular spot.
Most plumbing codes specify an approved Machine Applied coating, which pretty much means hand wrapped piping is out of the question, excepting the portion of the pipe stripped of it's coating for threading purposes and the fittings themselves, which are wrapped with 3M PVC tape.Quote:
Can black steel be used underground if it is painted with anti-corrosive paint and wrapped with 3M?
I have used coated pipe up to 2" for underground burial in the past, but noted years later when asked to install another branch for an additional appliance that the hand wrapped portions were beginning to rust out.
Consequently, we have moved on to GasTight flex for underground burial, which we sleeve with Schedule 40 PVC piping and long sweep fittings.
Pretty much the only time we will use galvanized piping in a gas installation is when we are penetrating masonary, usually for a log-lighter valve or outdoor BBQ.Quote:
Even the galvanized steel underground pipes still need to be wrapped with a special protective tape (like 3M).
Coz if the pipe is subjected to serious scratches, the coating would be removed at some point, leaving the pipe exposed to rust at that particular spot.
You do not use galvanized iron pipe for gas lines. The galvanize flakes off and clogs the orifices. We use threaded black iron or type "L" or "K" soft copper with flared joints for our gas installations. Regards, TomQuote:
Originally Posted by doug238
1- When I was referring to wrapping the buried galvanized pipes, I was talking in general and not specifically for gas applications.
2- So, in summary, for LPG outdoor underground applications, the choices are:
- black steel with factory applied anti-corrosive coating (the extra 3M wrapping, if costs
Permit, is a plus).
- GasTight flex, sleeved with Schedule 40 PVC piping and long sweep fittings.
- Type "L" or "K" soft copper with flared joints
And the choices are the same for indoor application, I assume. Though copper seem to be the most popular trend in that respect.
Hmmm...Quote:
Originally Posted by coolpj
Were we always talking about propane in this discussion and I just missed it?
I probably should have mentioned this before, people.Quote:
Originally Posted by iamgrowler
I am currently working in Africa.. Angola , to be more specific.
So here it's more of a European style.
Therefore we use LPG (Liquid Petroleum Gas).
Paul
Well...
Having never plumbed in Angola...
I don't know what your situation is regarding the availability of materials -- But if you're shipping in materials and tools from outside the Dark Continent -- It would probably be better to go with copper tubing and flared fittings. The tool needed for flaring copper tubing is a durn sight cheaper and lighter than a pipe threading machine, cutter, reamer, dies and ratchet assembly.
Also, be aware of the metric conversions if using materials purchased stateside and propane tanks and regulators of local manufacture.
Indeed, when it comes to LPG, for indoor applications, copper tubes are available, they usually have a protective layer (PVC, I assume).
But is copper piping recommended to be buried underground as a main pipe?
Going to hafta disagree here tom. Probably 95 % of the gas pipe in pensacola where I learned plumbing is in galvanized. Same in orlando. I did not see black iron in residential until I came to atlanta 6 years ago. And even here, the gas pipe exposed to rain is mostly galvanized.
Say, Doug, what does the IPC say about using copper tubing for LPG, more specificly, what does it say about underground burial?
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