The Stovebolt Site Forums The Shop Area The Tool Chest Compressed air and sprinkler valves

I have two shops at home about 200' apart and would like to use my big compressor for both. Piping is no problem and I can use a contactor to turn on the compressor from my remote shop but since the air bleeds down in the lines and the tank is large so a pump up from empty takes a while I need to be able to shut of the lines when not in use. Home Depot has a 150 psi solenoid sprinkler valve for $12 that sure beats a $400 air valve. Any idea if these would hold up under 90-100 psi air?

I wouldn't trust anything that sells for $12 at Home Depot. Just because your piping is 200' apart doesn't mean it should leak. I have a remote tank over 200' away from my compressor that I leave on all the time. I have a total of about 12 hose reels. I have a ball valve at each hose reel. I have 2 10HP compressors that run alternately and I never hear them running unless air is being used.

Yep, a simple ball valve is the ticket.

Think I would go around with bottle of soap solution and find and fix leaks. Hopefully none are underground.

Hopefully you did not use steel pipe underground, ran it on slope to drain it (air lines make great condensors and water catchers) AND buried well below frost line.

Dan Bentler

It sounds like some ball valves at the hose reels might be the way to go. I'll definitely be running PVC for the underground segments. Fortunately I'm in western Oregon. Do we even have a frost line here?

go to your local plumbing shop and ask for an ASCO solenoid valve, they're cheap and they come in all different voltages, and NPT sizes, and they don't cost any where near $400.

PVC is NEVER recommended for compressed air even by the factories. It can fracture and possibly blow chunks all over. There is a PVC built especially for compressed air but you better have a water cooled check book when you buy fittings.

I cannot remember what the code is for Seattle. Commonly I believe it is 18" for frost. 200 feet use a ditchwitch and set deep as possible. Long as you are at it throw in a couple conduits for electrical and a water line. Try to slope pipe in direction of air travel to keep line drained as much as possible (JOKE you are of course on dead flat level ground). Plumb in a drain valve at end to occasionally blow water out. I would look into using PEX for this application OR a plastic tubing (polypropylene ??) pulled thru a conduit so if (WHEN ??) it fails all you have to do is pull in another chunk of tubing and NEVER have to dig again (only cause you designed for failure - Murphy and his danged law)

ASCO valve designed for purpose at 1/4 or 1/2 should be around 50 to 75. They will probably have water air and oil designation. Use ball valves as much as possible.

Dan Bentler

Common valves and fittings are WOG (Water,oil,gas)rated.
And definitely agree with Dan, don't use PVC, it does shatter.
Even "K" code copper will work.

Type "K", "L" or "M" can be used for compressed air. I prefer to run airlines above ground. Leaks are a lot easier to find. I ran about an extra 100' along a security fence to stay above round. Some of the concrete around our shop is over 50 years old and there are several abandoned airlines under concrete that were abandoned instead of breaking concrete.

I agree about not using PVC for compressed air. A friend of mine is using PEX for his shop lines.

If you were to use PEX tubing, you don't want it exposed to the sun. The PEX tubing will deteriorate.

What ever you use, make sure the hose runs downward at 1/4 per foot with the lowest end at the end of the line so water can drain out.

I've worried a little about the PVC. Only about 20' is underground and the rest will be in a crawl space until it pops out in the shop. So PEX will handle a decent amount of pressure 90-110 psi.

The original plan was to run some low voltage to the shop for an alarm but I thought since I have to dig through 3/4 gravel and 3" pit run I might as well do the air too. Great idea to also run a couple of extra conduits for future water and power.

I ran a 4" PVC conduit from my house to my shop. That way I can fish a Cat5e, pex tube, cable, etc., if there is a problem down the road. I ran PEX through it so I could use my shop air in the house during its construction (air nailer, stapler, etc.), Then I ran it to the garage so I could use the air for my car tires, etc.

Read the last post in this thread.

The last post Tiny referred to said
It'll say something like 180psi at 70*F
150psi at 100*f,
100psi at 200*F, meaning that as the temperature goes up, the pressure rating goes down. But that's not the same as saying pex can't handle over 100psi.

The first thing is those numbers do NOT appear to be factory ratings do NOT trust them.

They are still very important - most plastic material pressure ratings fall with increasing temperature.

Since many compressors are set to shutdown at 125 I would say that if PEX is factory rated at 150 F and 150 PSI then it would be all right for 125 psi service. Would be a little leery of 150 psi or would want air to be cooled to below 100.

Dan Bentler

Reading the posts, I will throw my 2 cents worth.
If you run some 1 inch black plastic pipe used for sprinkler systems, this would make a conduit for any flex air hose inside. This irrigation pipe comes in rolls,and is relative cheap and lasts a ling time.The air hose can be removed to fix leaks,etc.

Just go to Menards and look at the PEX tubing they have there. The pressure and temps are printed right on the PEX tubing. The Pressure does decrease as temp rises. When it is cold it withstands more pressure. If one were to bury it below the frost line, the temp would be approx 50 to 58 degrees. Well below any temp rating given. That being said, it will withstand 125 psi just fine. When placing PEX for radiant floors, it is pressurized to 100 to 125 lbs for 24 hours for testing before pouring concrete.

Dan, the poster said those figures were written on the side of the tubing. I looked at the PEX in my mechanical room and it says 180PSI @ 73.4 deg and 130PSI @ 120 deg.

The drift I got was his numbers were (maybe ??) not directly off the tubing.
Yours ARE -
so it just might work OK with those ratings especially after the air is cooled some. Think I would take it out of the receiver to let as much water drop out and cool the air before running thru underground PEX

Dan Bentler