Not the usual pvc air line question

[mikeyr]

Let me start by saying, I know it is NOT safe to use PVC lines for air. No need to have that discussion, I know it is not safe and I have said so many times right here.

I need to get air 270feet from my garage where my air compressor is, just enough air to inflate tires, occasionally run a impact, minor stuff like that. I have a small slab in the corner of my yard where I store my rarely used trailer and truck along with the rider mower, I am in the process of getting electrical power to the area and I really would like to get some air there as well.

Using copper or iron pipe would be expensive and I am thinking of running PVC which I think would be ok since it would be buried in the 24" trench with the power line. I was thinking, lay the electrical conduit, put in a few inches of dirt and then lay the PVC on top and fill it up, it would be buried about 20" I am guessing.

ALL exposed parts would of course be copper, just the underground part would be PVC, think that would be ok ?

 

[Charles (in GA)]

That is what I would do.

Note that the OSHA bulletin that everyone (including me) usually cite in the PVC arguments is titled "Safety Hazard Information Bulletin on the Use of Polyvinyl Chloride (PVC) Pipe in Above ground Installations".

Charles

 

[sberry]

I have about a thousand feet of it in ground, one of the lines has 175 on it 24/7. I use covered or metal risers.

 

[Ray-CA]

If you really wanted to, you can always run a double wall type of pipe. For example, run a 0.75" pipe inside of a 1.5" pipe with the pressure in the smaller pipe. That way, if you do have a failure, it would most likely be contained and you would still have air without having to dig up the entire length of piping.

Ray

 

[Falcon67]

I'd do that - I'd also put a locator tape or at least some treated boards about an inch or two above the PCV to protect it in case there was digging and the pressure was on.

 

[A_Pmech]

I'd run a 1.25" sch. 40 PVC line inside a 3" DWV. That way, should you ever have a problem, all you have to do is dig up one end and snake a new one though. I'd put the electrical inside plastic conduit and run it out in the same 3" pipe.

 

[brownbagg]

or you could lay a rubber air hose in the trench

 

[nate379]

I ran 1.5" conduit and put a 3/4" rubber hose. Just finished the trench a couple days ago actually. I only had to go ~90ft though.

 

[Uncle Buck]

If you bury it to that depth, you will have removed the hazard by covering it with the dirt. That is a substantial depth for sure.

 

[nate379]

I would go at least 2 feet for sure. OR do like the PO of the house I rented in Idaho did and bury the wire to the shed about 2" down. I about cut it in 1/2 with the mower.

 

[-B-]

Pex tubing will work quite well for the application too and have only two connections in the run.

 

[d110pickup]

I used Pex to run from my shop building to the basement of my house.
Mike

 

[mikeyr]

glued up 300ft. of PVC, pressurized it and leak tested my joints, no leaks, let the air out and its in the trench.

The guy that did the trenching dug it about 28" to 30" deep so the electrician will put the electrical in, then a few inches of dirt and the air line, he wanted some separation from the 2. I am guessing it will be about 24-26 deep, I will sweat the copper ends this weekend and put it all together.

used 1" PVC because I had it around and ran 1 1/2 for the electrical, plenty of space to run more wires...Can't wait till the weekend, I might have to let out the air in my trailer tires just to re-inflate them

 

[Piper]

completely off the wall idea. I used a pancake compressor for years to run my impact occasionally, pump tires etc. They're about $100 on sale. Maybe you could just get one of those rather than going to the trouble of running and protecting the line?

 

[MrMack]

I thought about digging a ditch and pipeing from the shop to the equipment garage but decided to use a 3 HP compressor on 110VAC in the building, I got it at a swap meet for $150. I just switch it on when I need the air. It will run a impact for a few minutes, and a paint gun for long enough to prime and spray panels and parts, since it has a 60 gallon tank.

If I had of needed to run an underground power line, I would have put in a 3/4" PVC airline in the ditch too.

 

[dreamingmuscle]

Too reduce the chance having to dig it up because it busted. Install a pressure regulator or a ball valve. That way you can either turn the air off when not in use. Or keep the pressure low reducing the stress on it.

Just my 2 cents


P.S. If you use a ball valve to shut it off. You might want to install some kind of valve to let the pressure out also.

Another 2 cents
________
Mercedes-Benz W111

 

[nate379]

Reason I ran couduit and a 3/4" air line is in case it freezes or breaks I can just pull the line out instead of digging up the yard. I went down 36" (as deep as the trencher would go) and insulated it with pipe wrap and 4" of blue board.

 

[InPrimer]

I would look on Craigs list or?? and find a used 30 gal compressor on wheels, load it up in the garage and tote it out to the site, all that digging and possible leaks gives me a headache LOL

 

[djd99]

I would look on Craigs list or?? and find a used 30 gal compressor on wheels, load it up in the garage and tote it out to the site, all that digging and possible leaks gives me a headache LOL

This would be the easiest solution less labor intensive route. Also I don't hate the idea running pvc underground, it would be cheap and any risk of the pvc rupturing is underground.

 

[mrb]

when transitioning from pvc to metal, make sure you have a male threaded adaptor on the pvc pipe threaded into a female fitting on the metal piple. A male metal threaded into female pvc can cause the female pvc fitting to develop a crack and split.

 

[twostory]

Pex tubing will work quite well for the application too and have only two connections in the run.

I would run 1.5 inch PVC, then pull a continuous 3/4 inch PEX tubing thru that. The PEX would handle the air pressure, and you can pull and replace the PEX if anything goes wrong. Also PEX is fairly cheap.

 

[IH82BL8]

I need to get air 270feet from my garage where my air compressor is, just enough air to inflate tires, occasionally run a impact, minor stuff like that.

What about a portable air tank. You might already have one.

 

[mikeyr]

No, I did not have a small portable compressor, I own a really big compressor and never saw the need for another one. The point was in this case that I already had the trench cut for the electrical so putting in the air line was easy and cheaper than a small compressor. I wanted the electrical out there and that meant I had to have a trench anyway.

I do have a small portable air tank and that is what I have been using and was very tired of it.

Good point on the male/female connectors a few posts up, did not think of that one and did it correctly by accident.

 

[HoosierBuddy]

Based on my years of experience with underground natural gas lines (both steel and plastic) I would buck the trend, and recommend against using PVC.

Polyethylene is the material of choice for running compressed gasses underground at pressures to 100 PSI. The materials I've used are typically limited to 100 PSI by federal code when used with natural gas. Personnally, I would trust them with more pressure than that if I was putting air in them.

Of the miles and miles and miles of polyethylene I've run in natural gas service, I've never seen a material failure. Polyethylene pipe is not hard and rigid like PVC. It's flexible. In situations where it has failed (like when someone hits it with a backhoe for instance) it just gouges or tears or gets cut due to whatever hit it. It doesn't shatter or break. In fact, it will take a good bit of abuse before it breaks. I've seen a couple of instances where a 2-inch or 3-inch PE gas line gotten hooked by a backhoe and pulled all the way out of the ground without breaking.

Polyethylene joints are made with special heat fusion equipment that melts the pipe together or melts it within a coupling OR with mechanical couplings such as "stab" couplings that are pretty straight forward and foolproof.

Your ends where you come above ground could be accomplished with anodeless risers that transistion you from horizontal plastic to vertical threaded steel.

That's how I'd do it. It'd last 1000 years.

Trivia that most people don't know...The U.S. allowed PVC to be used for underground natural gas for about a 2-year period in the '70's. Then it got banned. Want to guess why?

One more thing...you can't use PE above ground because it will degrade if exposed to UV for long periods of time (like a few years).

Phil

 

[IH82BL8]

I already had the trench cut for the electrical so putting in the air line was easy and cheaper than a small compressor.

Oops, i missed part of your original post. If you're trenching anyway, by all means put an air line in the ground, too. I guess the question now is, should you put the air line on top of the electric to protect the electric from being dug up, or the other way around?