OT---Iron air line

Jiles · Aug 9, 2014

I ran the air supply from my shop to my upstairs garage. I used new AMERICAN made 1/2 black iron pipe and fittings.
My problem is with the 1/2 unions, they are the ones with brass? inserted seats.
I have a total of five with three leaking from the seats, not the pipe threads. After tightening as tight as practical, I removed them and polished the brass seats with scotch-bright and lubricated the nut threads. I reinstalled them and only slowed the leak.
I am running 150# of pressure and have never run into this with USA made fittings.
Defective fittings??

Hoenes · Aug 9, 2014

I've seen an old plumber coat the male part of the
union with teflon pipe dope, and had good results
with water. 150 psi may be too much though.

Dalex · Aug 9, 2014

Unless the fitting says USA on it , it is Chinese or Korean ....You see the proof.

Ken-Pa · Aug 9, 2014

Installed black iron pipe ? Years ago when I was over seeing new compressor installations so they were within warranty stamdards , using black pipe was a No No . It was proven that moisture build-up can cause rust to form & cause problem issues in air tools & paint jobs .HTH! God bless, Ken

h]t]]h]

Chris(WA) · Aug 9, 2014

Defective fittings or incorrect installation. You
may have to really reef them down tight. A union
should seal without tape or pipe dope. That is why
they are made the way they are. I have seen
inspectors reject taped and dopes unions.
Plastic is really the way to go with air lines
these days.

Jiles · Aug 9, 2014

(quoted from post at 18:47:31 08/09/14) Unless the fitting says USA on it , it is Chinese or Korean ....You see the proof.

Even if it says--USA--, and it does, there is still some dought!!
Plumbing supply store sells both American and foreign. I always request USA and pay a little more.
I might add that the entire run is bind free.
Leaks are not excessive, only a few tiny bubbles and most people wouldn't be bothered or even check.
A few pounds per day --three or four---is no big deal.

Bob · Aug 9, 2014

Take the unions apart and clean the sealing areas and apply some of this stuff...

<img src = "http://cloudfront.zoro.com/product/large/2LPP2_AS01.JPG">

Dr. Walt · Aug 9, 2014

Don't worry about the little stuff.

When I worked in The Mines, we had two huge
Ingersol-Rand Screw-Compressors putting out high-
volume compressed air at 200 PSIG and piped
through 6 inch steel piping coupled with Victaulic
Couplings. We had over 10 miles of air lines, over
1000 feet underground, just to supply air to the
Jacklegs / Rock Drills and the Air-Track Drills.
I'd say at least half of all the couplings we had
leaked a little bit of air - (extra fresh air in
an underground environment is a GOOD thing).

Doc :>)

Spook · Aug 9, 2014

This. Costs a bunch, but we used it in the factory for 3,000+++ hydraulic lines. 150 psi really isn't much. I've struggled with teflon tape, couldn't get it to work, put the Loctite on, and no more leaks.

showcrop · Aug 9, 2014

when I had a problem with a union in a water line not wanting to "make up" it was usually curable with a tiny bit of grease, ( I used silicone) on the union mating surface.

OT---Iron air line

Jiles

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Hoenes

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Dalex

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Ken-Pa

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Chris(WA)

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Jiles

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Bob

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Dr. Walt

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Spook

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showcrop

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