Running compressed air underground

[Royk]

I'm building a detached garage in addition to the attached garage I currently have. I want air in both, but don't want to buy another 80 gallon compressor. What would be the best thing to use to get air from one garage to the other underground?



Roy

 

[GHarman]

Royk, There are probably many views on this. I will give you one idea that may work very well. Oo. If you can get access to polyethylene Natural Gas piping from a Utility Supply and mechanical couplings or Heat Fusion irons to join it to a riser at the attached garage and a riser at your detached garage. This material is widely used in the natural gas industry for distribution piping and will carry all the pressure you need. It does not corrode, it is flexible and light in weight an will carry more volume of gasses than equivalent steel pipe because of the smooth internal finish. The initial cost is a little high if you use the Natural Gas risers at the buildings, or you can make your own. If you use Heat Fusion to join the pipe to steel you will need transition fittings (and socket fusion couplings)that can also be used with mechanical compression couplings ( here you will need an insert sleeve ). Be aware of the volume you will need and size your pipe accordingly, ie; die grinders, etc. Sorry we are so far apart, I have a length of 1 1/4" PE that I would give to you. :{ GregH

 

[sag2]

Schedule 40 PVC will work just fine. I have used it to plumb air from the compressor to where I need it in all my houses. I ran a length under a new driveway I poured two years ago and now I can air the motorhome tires without running hose all around the house.

I see your in the cold country so you might make sure the air is dry before you run it under ground so it does not freeze. You can also add sprinkler drains to it so the water can drain out when it is not pressurized.

 

[KcoleKennyc]

My machine shop is plumbed with sch 40. It's been in use for 20 years with no problems. Ran over 100 feet underground to a shed so I have air for the camper tires. Haven't had any problems with it but I am in the south.

 

[Royk]

GregH,



Sounds like a good way to do it, but out here in the sticks, it sounds hard to get. It also sounds kinda complicated. Thanks for the idea.



sag2, kcole,



I originally thought of pvc, but thought it might be too brittle. I'm thinking it might crack with frost heave in the winter, though I guess if I put it deep enough I should be OK.



Roy

 

[PToombs]

Roy,if the ground is covered with snow, the frost barely goes in. If it's under a sidewalk or the driveway, it goes in deep. The snow insulates the ground great!

 

[tgordon]

Roy, if you go PVC keep in mind the risers, are they in a heated area? My main concern with running it under ground is in the winter if they are not low enough and you get moisture in the pipe it could freeze, unless you slope it and install a drain. This is compleetly dependant upon how much and what you use the line for. IMHO I would simply plumb the barn with it and put the compressor in there and have plenty of hose on a reel if I needed it in the garage.



Troy

 

[Royk]

IMHO I would simply plumb the barn with it and put the compressor in there and have plenty of hose on a reel if I needed it in the garage.

Troy

I might just do that. The new garage won't be very far from the old one. I could just lay a long length of hose from one to the other. It would be a lot simpler and cheaper. However, if I end up keeping my most flat tire prone vehicle (the tractor) in the old garage, the convenience of readily available air would be real nice. Not to mention the ability to blow things out, off, etc. . I guess I'll just play it by ear for now.

 

[tkerrigan]

Use PEX tube. 3/4" is cheap, freeze proof, and easy to run.

 

[JasonCzerak]

And since you'll have to garages, you'll need them things the banks use to get your tools from one garage to the other

 

[BGlidewell]

And since you'll have to garages, you'll need them things the banks use to get your tools from one garage to the other

armored cars?

 

[Mhannink]

armored cars?

no i think he means those cool little vaccume tube thingy

 

[RandallScot]

RoyK, FYI the pe pipe suggested by GHarman is only rated to carry 60 psi. We do test it @ 100 psi for 5 min. , but then again, an air leak would not be nearly as bad as a nat. gas leak. Someone who works with nat. gas on a daily basis in Cal.

 

[GHarman]

RoyK, FYI the pe pipe suggested by GHarman is only rated to carry 60 psi. We do test it @ 100 psi for 5 min. , but then again, an air leak would not be nearly as bad as a nat. gas leak. Someone who works with nat. gas on a daily basis in Cal.

Just to let you know; 10 years experience in natural gas distribution utilization and maintainence, including welding hot taps on HP natural gas piping. The pipe I recommended (Dupont TR418, my offer) was more than adequate to carry the pressure and volume needed to run the air tools including a die grinder or impact wrench. There is a safety factor built into pressure piping that is more than adequate to carry air for a non critical application. I would not be hesitant to use PE pipe for this application, given availability. It is only sounds more complicated than it really is. GregH

 

[GHarman]

Just a further note. Years ago, 60's-early 70's, Public Service Co of Colorado experimented with glue fused PVC pipe as distribution piping. It was more severly pressure limited than the PE pipe ( DOT regulations enter here ). We were going out on leak calls regularly on this batch of PVC. On one of these leak calls on a 4" distribution line, we dug it up and in the process of exposing the 4' or 5' of pipe in the bottom of the hole with a shovel, my partner John Carson tapped the pipe with the flat of his shovel to knock off a clump of dirt and the pipe shattered, blowing splinters into his face and neck. I was only a few feet away when this happened. 1978 time frame. GregH

 

[Flinty]

I'd run conduit big enough to have pex or some other flexible line pulled through it. If you have any problems, pull a new line.

 

[GHarman]

I'd run conduit big enough to have pex or some other flexible line pulled through it. If you have any problems, pull a new line.

Sleeving is an excellent idea. We used to insert PE gas pipe into a larger diameter , old steel gas fuel pipe from the street to the gas meter, After digging at both ends and creating a new riser and tying the new PE pipe into the gas main. Same idea. GregH

 

[MAshley]

you could also get the black polly water line pipe. Go to a water supply store and you can get the thincker stuff instead of the thinner Home depot stuff, same idea as the NG line just ment for water, and I would bet good for 200 + psi. easy to work with, I wouldn't worry about frezzing and lots of air, I would run a 1 inch miminum if it was me

 

[South Dakota]

Schedule 40 PVC will work just fine. I have used it to plumb air from the compressor to where I need it in all my houses. I ran a length under a new driveway I poured two years ago and now I can air the motorhome tires without running hose all around the house.

I see your in the cold country so you might make sure the air is dry before you run it under ground so it does not freeze. You can also add sprinkler drains to it so the water can drain out when it is not pressurized.

Never run compressed air in PVC. It can explode and act like shrapnel causing injury or worse. Copper or sch 40 steel pipe would be much better. If your going to bury it you will need to apply pipe wrap primer and a 10 or 20 mil pipe wrap with 50%overlap tp prevent corrosion. It is also a cood idea to install a die-electric nipple or union to help with electrolosis. When above ground make sure you slope your line to a drip leg that you can blow down once in awhile to remove moisture. Also a good idea to run your drops off of the top to prevent moisture from reaching your air tools.

 

[MAshley]

I don't think we all need to get in a flame war about what to use, Most peopel agree PVC works, but may have some flaws-risk factors, Steel pipe works, but it also has flaws, rust, Black polly pipe works, shoot a rubber line would work, but basicly you need air, dont' want to mess with it ever again. So pick your favorate pipe, big enough to run the required CFM and then make it the next size bigger. good luck and have fun