compressed air question

[68bbc/20]

i'm getting ready to run air about 80 feet to an addition I built on my pole barn
what size, what kind of lines have any of you plumbed your shops with? any special features you did for future use or equipment that might be helpful to
set it up for now while i'm running it? thanks for any input you can recommend. Les

[jcwren]

Do NOT use PVC. That's a fragmentation bomb waiting to go off.

[AussieinNC]

It all depends on what you intend to use the "air supply" for?

Most economical is 1" galv pipe...but if the end use is as a spray booth supply...save yourself a huge headache and put another compressor out there....

When plumbing air lines you MUST include drop points with drain valves in each vertical drop line....below the outlet nipple....

Dryers are nice...keeps moisture out of your air tools...(and paint!)....

In long runs, I try and install a ballast tank to provide more air supply load balancing...an old compressor tank works well....

Hope this helps...

[jcwren]

Originally Posted by AussieinNC

It all depends on what you intend to use the "air supply" for?

Most economical is 1" galv pipe...but if the end use is as a spray booth supply...save yourself a huge headache and put another compressor out there....

When plumbing air lines you MUST include drop points with drain valves in each vertical drop line....below the outlet nipple....
<chop>

And cut-off ball valves at logical places.

[68bbc/20]

both are good replies.

[B. W.]

With a run that long I'd go with at least 2" pipe. With a smaller diameter you may run out of air even though the compressor & tank are large enough to supply it.

The great thing about a long run is that your air will be dry. Run it slightly uphill & put a drain at the low end.

And the guys are right about not using PVC but if you are burying the pipe I'd have no issue with it. I have about a 40' run of 2" PVC buried at my shop & have had no issues. If it were to blow no one is in danger. ( been under ground for about 15 years now)

The extra tank that Aussie recommends is a great idea also.

[franken]

The issue w/ PVC is it gets brittle when exposed to UV or sunlight or whatever. No bueno for compressed air.
Run air down and no drain at the lowest point and you'll have bad air forever. That means if you want to bury the lines bad things will happen.
People say galvanized pipe flakes the zinc off and blows it through the system so use black pipe. People say black pipe rusts so don't use it. I say design a system where water can't collect.
My theory is water should be caught in the tank (always collects here), in a dryer (might be a simple filter/dryer) or pushed out at the end. Cruel, but the air system purging itself mostly automagically is the important/best part. People pushing multiple drops in a 2 car garage or multiple ball valves are delirious.
My system is log horizontal runs and short vertical runs with unions. It's modular so you can take it apart.. Then at the end, I have a short horizontal run w/ a union where the filter dryer regulator and outlets live. All simple stupid modular expandable shrinkable and made with crap from the home store.
Don't believe me; read up on small shop air systems. Then again, the internet is full of crap.

[jcwren]

Originally Posted by franken

People say galvanized pipe flakes the zinc off and blows it through the system so use black pipe. People say black pipe rusts so don't use it. I say design a system where water can't collect.

What people really say is use copper pipe. But who can afford that, these days?

[Daaaanz67]

My friends auto shop uses PEX. 3/4” on the main runs with 1/2” drops. Seems to be working well for him.

[Coley]

Ok, a couple of important questions to get some needed information:

1) What is the max. pressure that you want to produce? or will be available from your compressor?
2) Are you burying this air line or will it be on the ground or overhead or in a building? (heated or?)
3) Is this 80ft a straight run outside?...or is it 80ft equivalency of a variety up bends, height changes etc as it weaves through and to your new addition?

....lets start there and we can help sort this out.
All good
Coley

[68bbc/20]

it will be inside a pole barn up and dropped down the walls and thru the trusses 40 feet to reach my addition. building is not heated. I just want air for tools at this time, may consider painting later on down the road.

[68bbc/20]

tank kicks off at 130lbs.

[AussieinNC]

PEX is not stable when exposed to light...it will degrade....its meant to be used indoors or in crawlspaces or walls...

Black pipe or gal pipe....just keep it running slightly down hill to a drain port and drain all lines once a month in Summer....once every two months in Winter....

[franken]

Originally Posted by jcwren

What people really say is use copper pipe. But who can afford that, these days?

The typical answer is use black pipe, but then people whine about it rusting--in 50 years. Design and build a system where water has to flush out and your grandchildren could be using the system at the end of the century.