air line under ground

by kyle
(dixon, il)

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 flexable hose that would cost less and be easyer to install than pipe? I plan on using it mainly to air up tires and occasinal work.


Thanks, kyle

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Bill says...

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

Another consideration is rust from ground water, so that would leave pipe out for me.

If you bury it far enough, then you'll avoid heat/cold issues, but if you don't, moisture in the air and condensing in the air line outside in the winter could be a problem.

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. That won't give you much flow after a 100' run due to pressure drop, so 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 pipe.

See the PRESSURE DROP pages for flow info.

Consider reading the pages on this site about Water for more info about this problem too.

Cheers,

Bill

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air leak from pipe clamp

by Derek
(UK)

Hya - Fantastic site!!
I had a leak problem in a new air pipe which I returned for a replacement which sadly had the same problem.The air escape is from the pipes own coupling where the pipe is clamped on to its female connector. Is there any remedy other than just another replacement which may also be useless
respectfully
derek

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Bill says....

Derek, I need more info about what type of pipe and what type of coupling / connector.

Post a comment here with details, please.

Bill

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drain valve won't reseal after opening

by Carl James

Drained tank like I was supposed to, reinstalled nut. Now air flows out of it freely.

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Bill says...

Carl, does the air flow when you rotate the nut both ways? By this, I mean, turn the nut all the way to stop one way. If air continues to flow, turn the nut all the way to stop the other way.

If air continues to flow after turning the nut all the way to a full stop in both directions, and by the way, mine does not "screw off" like it sounds like yours did, then it's likely time to replace the valve.

Cheers,

Bill

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Check valves installed ?

by Roger Bates
(St. Johns, Michigan)

We have 4 air compressors in our shop, all are piped into one system. My question is should they have check valves installed to prevent one unit from pressuring another unit. 3 units are piston type one unit is screw type. The screw type is our main unit others turn on as more air is needed.

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Bill says...

Roger, I would have a check valve installed in each of the lines from each compressor before they reach the common manifold. As you point out, you don't want air from a running compressor flowing back down the line to a stopped air compressor, which has it's unloader valve opened to atmosphere.

Cheers,

Bill

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CFM needed for sand blasting

by Randy Murphy
(Piqua Ohio, USA)

I purchased a Snap-On Pressurized sand blaster, Model Y441 pressurized tank @ 80 psi. It has a 1 inch delivery hose coming out of the tank. I have hooked up the supply line, which is .5 inch copper feed line, with a .5 inch hose. Snap-On rep. said this unit should blow paint off down to metal with no problem. It take me two minutes to get a 1 square ft. area and lots of media. Please help suggset a fix.

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Bill says....

Hello Randy. From your post I understand that you feel that the Snap-On Pressurized sand blaster may be being under-powered by the .5 inch copper supply line versus the 1.0 inch delivery hose.

Am I correct in understanding that the 1.0 inch hose is the media delivery to the blast nozzle, or is that the compressed air supply to the blaster?

Randy, I don't do much blasting, so I don't know if 2 minutes to get 144 sq/inches of metal back down to clean profile is fast or slow.

I do believe that somewhere in the specs for the sandblast unit it should tell you what the compressed air feed flow rate for that blast gun, at 80 PSI is. That's the info that will tell you whether you have enough flow or not.

What's that spec, please? If you can't find it, ask the rep.

The PRESSURE DROP page on this site has a chart to give you some idea of the flow through various sized orifices.

Cheers,

Bill

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Higher Temperature

by James Ross
(Peterborough On, Can.)

The environment sometimes reaches +140F and we have polyethylene tubing failures. Is Nylon a better choice for us for compressed air at 95 psi ?

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Bill says...

James, PE tube has a temperature rating, and if the ambient exceeds that, then you will have failures.

Fortunately, the tube failure generally results in a "bubble" that pops, and bleeds air. Not much danger issue there.

Look critically at the "real" temperatures your air plumbing will see, and use the correct air line.

Why not stick with copper?

Failing that, find your air line plumbing source, and then ask them what their temperature ranges are?

Cheers,

Bill

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I broke the part that the gauges and regulator screw into, what is that piece called?

by Tom
(Florence SC)

I am trying to order a part for my pancake compressor. I broke the t shaped piece that the regulator and gauges screw into. I got a used one and it broke too. I need to know what the name of this part is so I can search it.

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Bill says...

Tom, I'd call it an air manifold. Why don't you visit your plumbing store with the old one, and buy the parts in copper to make yourself a new one? You could even change the orientation to better suit you, if that were an issue.

Cheers,

Bill

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plumbing regulators that fit on a 3/8 female connector...

by Mike

We have a system set up at the shop already. I don't want to redo a fitting. Are there regulators that fit on a 3/8 female connector to drop the pressure for a flexible air line.

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Bill says....

Mike, sure, you just need to put a male to male nipple of the appropriate size in the port of the regulator that you are attaching to the female port in the supply line. Any plumbing store will should have a brass fitting like this.

Or, you can get a regulator that snaps into the line, though that means that you would need to buy the install kit too.

Cheers,

Bill

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Converting an electric motor driven compressor to an engine driven one

by Derek Crawford
(Tasmania, Australia)

OK, I have a small air compressor whose pump has "died". I'm fitting a 15cfm triple pump to the receiver which is to be driven by a 5hp petrol engine. What different fittings or valves need to be changed or included in the new line from the pump to receiver or indeed to the receiver itself?

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Bill says....

If I take the line from one compressor, and attach it to the discharge from another compressor, I can see no need to change the plumbing at all.

I do not know what air treatment equipment you have presently between discharge and receiver, so I cannot be specific.

I am guessing that by "small" you mean in the 5 HP range before and now new?

Derek, that being the case, I don't see, unless I'm being particularly dense (not unusual) why you would need changes at all?

Cheers,

Bill

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