Steel Pipe Threading (Homeowner's Edition)

[Firebrick43]

Firebrick43 thank you for that informative reason why one shouldn't use PVC for air lines. That was all I wanted to begin with. If you would look back on my post you will see I never claimed it was safe . I just wanted to know why it wasn't. Is there a list of subjects that piss members off available that I can get ? I'm kind of new here so I don't know what is constantly asked or claimed. I guess I've never been on a forum where people get upset so easily.

I think PVC airlines is the smelliest topic to step in. A few get upset when you make fun of honda ridgelines but I still do it.

 

[sportfan]

I think PVC airlines is the smelliest topic to step in. A few get upset when you make fun of honda ridgelines but I still do it.

Ok, thanks.

 

[joshmodelskidoo]

Air line kit, Copper or galvanized is your best bet. Black pipe with moisture equals rust.

 

[Metallitubby]

What are you going to do about the inevitable rust that will form inside the steel lines? Compressed air always has moisture in it.

Drain the lines every day? The shop I currently do side work at hasn't had any rust issues in the 12yrs he's had his steel lines. He drains his compressor once a week on a timer.

 

[Metallitubby]

When picking up prethreaded pipe, check the threads with a number of fittings, like 90s and 45s. Then look for torn threads. Both the fittings and the threads can be of poor quality. It's only air lines, so more a case of ease of use.

Good information. Thank you!

 

[dr_clyde]

Thousands of shops use black pipe every day for compressed air lines. It works just fine. Every shop I’ve ever worked in and all of my own personal shops use black iron pipe for air.

Air dryers are a thing. It’s not rocket science.

 

[rustyjames]

Air line kit, Copper or galvanized is your best bet. Black pipe with moisture equals rust.

Galvanized pipe isn't what I've ever seen used for air because of internal flaking.

 

[sparky 1971]

There's nothing wrong with black pipe for air lines. I have a trucking company customer that has around 2500 trucks on the road with at least four locations across the country. They have miles of 1" black pipe in just the three locations I work at in little ol' IA. I have another customer that is (I think) the largest machine shop in DM. 100's of feet of black pipe in there. I know the trucking company has an air dryer, but not sure about drain ports at point of use. Not sure at all what the machine shop has, I will take a look at both next time I'm there. On my own system, I installed a ball valve with a drain port below each outlet (4). I open them when I think of it, but have never seen any water come out.

 

[Metallitubby]

On my own system, I installed a ball valve with a drain port below each outlet (4).

Something similar has been planned for mine as well.

 

[Steve from Socal]

I did about 500 feet of black pipe in my shop. We bought a Chinese power threader off Bezos and found the dies were junk. The older Rigid dies work in that threader and we were off to the races. The list of tools, dies ratchet/power handle, reamer, pipe cutter and pipe vise are essential. A large easy to use pump oiler or a small pump is also a must have. Missing any one of these items will make the job nearly impossible. You can use a file or rotary tool to debur the pipe but a reamer is so much faster and cleaner. A real pipe vise is the only way to do more than a piece or two.

Depending on where you are, a plumbing supply may have better quality pipe than Ace or the Despot. The pipe I used came from Turkey.

 

[metaldad]

i can only read 6 or 7 replies
im a pipefitter, metaltub.
iron pipe is preferred for air service.
i saw, you prefer usa manufacture.
not available at diy or local hardware stores.
you'll have to visit a piping supply house.
black pipe suitable for your needs is 'schedule 40' wall thickness
fittings are 150# wog rated.
unions, i'd upgrade to 300#, due the larger sealing surface.
you should have a means, to remove condensate from your supply air - another topic for somewhere else
you will need a pipe vise in whatever configuration available to you.
you will need a pipe cutter, with a sharp wheel, for a straight cut - a bandsaw or cut off wheel on a grinder wont do. (i have, i have made it work)
you should use a ratcheting handle die for threading.
you could use a non ratcheting one, it will take you longer.
threading oil. also, tilt your work downwards, so, the oil will drip off the threading end, instead of down the pipe.
you do NOT need to double dope a thread with tape and paste.
a quality paste on the threads will suffice.
tape is messy, can easily get cut and pieces get into piping, plus, it looks diy
your not building the space shuttle. piping aint that complicated.
if you lived near, everything needed is here, and, could be lent to you, for the price of a conversation over a beer or three

 

[metaldad]

and, i forgot, as i read steve's reply, you will need to ream the ends you cut.............. with a reamer.
pipe cutter, depending on how aggressive you are, and how sharp the cutter is, kinda squishes the pipe, reducing it's inside diameter in the process.

 

[Keep]

I was just going to say make sure you have good pipe dope. But Metaldad took care of that. Much easier then tape and it just works.

 

[matt_i]

Highly recommend Ward Mfg fittings for black iron pipe.

There may be other sources but McMaster Carr has always been a reliable source.

The box store fittings are leaks waiting to be found, and you can replace them but how many unions do you have to cut into your system to fix them (?)

I'd recommend spending some time with a file knocking off the bite marks from your pipe wrenches. They look bad and can snag you when not expecting it. If you intend to paint the exterior of the steel pipe (baby blue or ?) I would spend the time to paint the long sections ahead of time and then touch up with a little chip brush and cup of paint later.

I personally don't use teflon, instead Loctite PST 592, rated for oil, water, hydraulic, gasoline service.

What are you using to mount the pipe to the interior? Unistrut, or pipe-hangers?

 

[Metallitubby]

i saw, you prefer usa manufacture.
not available at diy or local hardware stores.
you'll have to visit a piping supply house.

I will start my research on this aspect. Thank you for the information.