Galvanized pipe for compressor run?

[crooklyn]

Is it ok to use galvanized pipe for my air line runs or is it better to stick with regular black pipe?

Thanks

 

[txvwnut]

It'll be fine, that's what I used in my shop.

 

[matt_i]

"it works" but its not the right stuff. The galvanization can break off in chip form and kludge up the works downstream.

If there's a choice use black iron (steel) pipe

 

[coljar]

I ran black iron myself, but we have miles of galv. air lines here at work and a good amount is supplying instrument air to millions of dollars worth of machinery.

 

[koditten]

I used galvanized electrical conduit. I don't know what the difference between that and galvanized pipe, but the price was $3 a stick cheaper.

 

[Streetbu]

I used galvanized pipe, been working fine for 8 years now.

 

[Radix2]

"it works" but its not the right stuff. The galvanization can break off in chip form and kludge up the works downstream.

If there's a choice use black iron (steel) pipe

yah, because we know steel pipe full of moisture, rust, oil, and gods knows what else never kludged up anything downstream...

I seriously doubt that ungalvanized is the right stuff for any reason other than it is the cheapest stuff sufficient to do the job.

 

[ryolse]

For those using EMT Conduit what did you do for joining then ends?

 

[coljar]

They didn't use EMT, they used rigid threaded galv. conduit.

 

[bob15]

"it works" but its not the right stuff. The galvanization can break off in chip form and kludge up the works downstream.

If there's a choice use black iron (steel) pipe

And what happens when the black iron develops rust inside? Same results.


To the OP:

Galvanized pipe is fine, as is black iron. Or to go all out, use copper.

 

[ryolse]

They didn't use EMT, they used rigid threaded galv. conduit.

Got it, the "I used galvanized electrical conduit" threw me off and I assumed it was EMT and not rigid.

 

[NUTTSGT]

I used black pipe for mine but I considered galvanized. I wanted to paint my some I went with black pipe plus it was slightly cheaper. As far as I'm concerned, either one is better than what I replaced.

 

[koditten]

No problem, I should have stated it was rigid, threaded electrical conduit. Sometimes I forget that not all of us have been around building materials. Sorry.

 

[ryolse]

Actually I'm a controls contractor who's around sites new and old for the last 11 years. We just always use EMT and use rigid very rarely except where it's required for explosion proofed spaces.

 

[crooklyn]

It'll be fine, that's what I used in my shop.

I ran black iron myself, but we have miles of galv. air lines here at work and a good amount is supplying instrument air to millions of dollars worth of machinery.

I used galvanized pipe, been working fine for 8 years now.

And what happens when the black iron develops rust inside? Same results.





To the OP:



Galvanized pipe is fine, as is black iron. Or to go all out, use copper.

Thanks all for the response. I will be using Galvanized especially as I'm able to get it for dirt cheap at work

What else can I make out of galvanized pipe? Maybe that's for another post

 

[rburke65]

ryolse.....you may have "been around sites for 11 years" but you have never seen EMT used for a compressed air lines!

 

[Techie1961]

Galvanized is what I prefer when putting in a new dry cleaning plant. I don't like black pipe and copper makes me nervous. If it was silver brazed, no problem but regular solder comes apart too easily in my view.

This is an example of what black pipe can look like after a few years. I have seen this more than a few times in a system where there is a lot of use and not the best water control at the compressor. I have seen lines completely blocked with rusty **** in them. This is what I managed to loosen up in a customer's air line with black pipe. The air line is shown disconnected top center of the photo.

 

[Techie1961]

Are some of you actually using electrical EMT for running air lines? Is it possible that some of the responses to this thread are referring to the electrical lines for the air compressors. I would never dream of using non-pressure rated tubing for air lines. That's what EMT is isn't it? Please clarify me if I am wrong.

 

[coljar]

Are some of you actually using electrical EMT for running air lines? Is it possible that some of the responses to this thread are referring to the electrical lines for the air compressors. I would never dream of using non-pressure rated tubing for air lines. That's what EMT is isn't it? Please clarify me if I am wrong.

Fortunately, you're wrong. Post #8,9,11,13 will explain what went down.

 

[Techie1961]

Fortunately, you're wrong. Post #8,9,11,13 will explain what went down.

Thanks for that coljar, I saw them and am still a bit confused. What is "threaded galvanized electrical conduit"? I've seen electrical ******* that are marked as electrical use and even those, I wouldn't use for pressure applications. Hoping to be educated here.

 

[Techie1961]

Thanks for that coljar, I saw them and am still a bit confused. What is "threaded galvanized electrical conduit"? I've seen electrical ******* that are marked as electrical use and even those, I wouldn't use for pressure applications. Hoping to be educated here.

Okay, found some answers. Rigid electrical conduit isn't pressure rated and should not be used for air line applications. There seems to be some discrepancy on whether they come with tapered pipe threads or straight and obviously, a threading die will cut a tapered thread if you are doing it yourself. Still, I wouldn't use tubing/pipe that isn't certified for pressure if it was me.

 

[ryolse]

ryolse.....you may have "been around sites for 11 years" but you have never seen EMT used for a compressed air lines!

And where did you assume that I ever said that I have ever seen EMT used for pressurized pipe or that it is appropriate to use?

 

[Charles (in GA)]

Thanks all for the response. I will be using Galvanized especially as I'm able to get it for dirt cheap at work

What else can I make out of galvanized pipe? Maybe that's for another post

3/4 makes good downrods for ceiling fans if you need a custom length, esp if real long. I made 4 ft ones from 3/4 galvanized water pipe. Just requires care to drill the cross pin hole and the drill and tap the threaded hole for the gound wire.

 

[Doozer75]

You can use regular thin EMT for air or water.
Copper elbows and fittings solder right on.
I know this guy that owns a local bar.
He is really cheap.
He plumbed the bathrooms with 1/2" thin EMT
and soldered on copper fittings. Still there and
that was over 20 years ago.
-Doozer

 

[Ironhorse74]

Copper is sexier.

Brad

 

[mike_dmt]

I've heard of guys using PEX. Would that be the cheapest option? I'm doing my air lines in the next week or two, so I've been kicking options around.

 

[yaidunno]

You can use regular thin EMT for air or water.
Copper elbows and fittings solder right on.
I know this guy that owns a local bar.
He is really cheap.
He plumbed the bathrooms with 1/2" thin EMT
and soldered on copper fittings. Still there and
that was over 20 years ago.
-Doozer

For the record, EMT is in no way rated for pressure, and should never be considered for compressed air applications, or even water. It's one and only use is a raceway for wire.

Just because Joe Shmo was cheap and scabbed together his plumbing does not make it correct.

To the OP, use a proven, pressure rated pipe for your install. Black, galvanized, or copper will all do just fine. Compressed air can have serious consequences if not handled properly. The difference in cost is should not even be considered when choosing a quality, safe air system.

 

[nadogail]

I used galvanized electrical conduit. I don't know what the difference between that and galvanized pipe, but the price was $3 a stick cheaper.

Rigid Conduit threads are the same form and pitch as pipe threads. The threaded ends are straight instead of tapered, so you will not get the sealing like you get with pipe joints.

Additionally conduit is not rated for pressure like pipe, so can not be depended upon to remain intact when pressurized.

In my opinion, conduit is a poor choice for compressed air use.

 

[matt_i]

If it leaks due to poor threadform, the $3 saved per stick will be long gone. Compressed air is very expensive.

Another view: galvanized pipe is unusable for natural gas lines....and those run either 1/4psi or 1/2psi...my understanding is because of the propensity of galvanized flakes to accumulate...my personal feeling is that's not going to alleviate under conditions with 100+ psi differentials.

Copper is of course highest cost and best practice. In my opinion, the solder to use is Stay Brite #8. It melts with a regular propane torch, flows like the old leaded solders (although no lead, NSF rated safe for potable water lines). Much higher tensile than your generic big box "lead free plumbing solder" and most importantly, the alloy will not "creep" under load. Of course, the solder also costs more too But, an important detail when designing a ~175psi pipe system rather than a 50psi potable water system.

 

[sberry]

I've heard of guys using PEX. Would that be the cheapest option? I'm doing my air lines in the next week or two, so I've been kicking options around.

These threads spin to nonsense fast.

Get a couple sticks of 1/2 black pipe and a few simple fittings to make a manifold to get to where you need it. Ball valve after the comp and then a hose to the pipe. I like to stick with 1/2 where I can, makes it so easy to fit and least use of fittings.

 

[JunkYardDawg]

I've just always used black pipe and painted it green per ANSI. Those practices used at work make sense in my home shop as well.

 

[sberry]

A lot of concepts people see at work are not practical for a home garage. Some of them downright not good ideas and the downside is a lot of expense and effort. They may also induce problems.
I would have guessed green was O2

 

[sberry]

When I entered the work world I figured I could outsmart the old guys that said use black pipe. These were guys 20 years ahead of me. Today my stock answer and if a bud wanted help piping a circuit in a small garage would use 1/2 black pipe as was suggested then. Its what old timers 20 yrs ahead of me still have.

 

[yaidunno]

I've just always used black pipe and painted it green per ANSI. Those practices used at work make sense in my home shop as well.

2007 ANSI/ASME A13.1 calls for compressed air to be blue with white markings. Green is to be used for non hazardous liquid. Please correct me if I'm wrong, but these are the standards I've seen and read about.

 

[koditten]

I have my own pipe threader. My threads are exactly the same as pipe threads. My compressed system is charged 24/7. I have no leaks.

I find the galvanized threads better. The black iron would tear while threading. I found this out while plumbing my gas lines.

Use black iron if you can afford the american made, not mexico black iron pipe.

I did want to see pics of this thin wall, EMT tubing soldered to copper.

 

[sberry]

I used some home store 1/2 black and did have to make a thread and it seems to me I recall something funny about it but I put it together on the floor farmertite and it didn't leak.
I am actually a fan of the box store pipe in the fact it is available and cheap. Its 10 ft and with even a small imagination can make up from ready made parts and when you get down short the selection of ****** length is super.
Most small garages would be well served by half a dozen pieces and half a dozen fittings. I have some pieces of galv in here and there, cant see as it hurts a thing.

 

[c39er]

I used 1" and 3/4" thick wall galvanized pipe 23 years ago... over 150" of it and never an issue.

 

[SmokeyBC]

I used PVC pipe, schedule 80 wall thickness. I put it in my home shop 12 years ago, no problems.

I know, but I've had no problems, and its easy to add drops and other changes.

 

[coljar]

I used PVC pipe, schedule 80 wall thickness. I put it in my home shop 12 years ago, no problems.

I know, but I've had no problems, and its easy to add drops and other changes.

Ok, the pot is full and the fire's going. Now where is that ladel?

 

[Kevin54]

I used PVC pipe, schedule 80 wall thickness. I put it in my home shop 12 years ago, no problems.

I know, but I've had no problems, and its easy to add drops and other changes.

Oh hell no.....PVC????