by kyle
(dixon, il)

Run an air line under ground? I want to run an air line from my shop 100 ft+ under ground out to a shed.

I was wondering if I can use some kind of flexible hose that would cost less and be easier to install than pipe? I plan on using it mainly to air up tires and occasional work.

Thanks, kyle

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Kyle, you can use any hose, tube or pipe that’s rated for the pressure of your air system.

One consideration is rust caused by ground water, so that would leave black pipe out for me as an underground compressed air line.

If you bury it far enough, then you’ll avoid heat/cold issues. If you don’t, moisture in the compressed air and condensing in the air line due to ground temperatures outside in the winter could be a problem with air line freezing.

Well - maybe not this deep, but under the frost line would be best

Well – maybe not this deep, but under the frost line would be best.

If I were doing what you were, I’d consider using 1/2″ poly tube, with no fittings buried (one length from inside to inside), and if I planned on using the air in the winter, I would have a desiccant dryer installed inside the source building to dry the air before it got into the outside pipe underground.

That size air line won’t give you a huge flow after a 100′ run due to pressure drop,but if you say it’s for very light duty, that size may be enough.

Or, you might have to opt for larger hose, and if you can’t get one big enough for the flow required, you may have no choice but moving to pipe.

See the PRESSURE DROP pages on this site for factors that affect the flow of air over a longer distance if you wish.

Consider reading the pages on this site about water from compressed air for more info about this problem too.