Pex and Sharkbites for low pressure air?

July 11, 2018, 12:11 PM

I want to run an air line in my basement, but I don't want the (noisy) compressor down there. The idea is to run a line to an external chuck and charge the system from the compressor in my garage.

I know PEX tubing is rated for air, and I'd really love to use shark bite fittings for the ends. They are not specifically rated for air or gases, but this would be regulated to a max of 50 psig, more likely 25. It's for airbrushing and a mist-coolant system for my lathe and mill.

Anybody tried this?

July 11, 2018, 12:32 PM

nshumway

I think pex is only rated for 100psi. I would use something like this

https://www.amazon.com/Rapidai...ords=Garage+air+line

July 11, 2018, 01:12 PM

PHPaul

quote:
Originally posted by nshumway:
I think pex is only rated for 100psi. I would use something like this

https://www.amazon.com/Rapidai...ords=Garage+air+line

I would too if I had the cash. PEX is rated for 180 psi @ 20°C (68°F) It's the shark bites I'm concerned about.

July 11, 2018, 02:34 PM

nshumway

Sorry I’m thinking worst case with hot water- not cool air. You have a piece with shark bites to test with? I have some I could send you or even test for you.

July 11, 2018, 03:57 PM

PHPaul

quote:
Originally posted by nshumway:
Sorry I’m thinking worst case with hot water- not cool air. You have a piece with shark bites to test with? I have some I could send you or even test for you.

I don't, but it's not a major investment.

In retrospect, I'm probably better off just buying a length of pre-made air hose and plumbing the ends as needed. Likely cheaper too.

July 11, 2018, 05:04 PM

ffips

The cost of shark bite fittings vs pex fittings and a single hand pinch crimp tool might be similar if many fittings are needed.

I could ship you the crimp tool if you return it when done. Tool I have.

July 11, 2018, 05:07 PM

arcwelder

You could run PVC without issue, many shops I've worked in have used it. It'll cut down on condensation issues.

I don't think pex/sharkbite would be a problem for air pressure, given the limits of a typical non-industrial compressor.

Arc.
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July 11, 2018, 05:21 PM

PHPaul

quote:
Originally posted by ffips:
The cost of shark bite fittings vs pex fittings and a single hand pinch crimp tool might be similar if many fittings are needed.

I could ship you the crimp tool if you return it when done. Tool I have.

Heck, that's cheap enough. If I need more than a couple of fittings, it'll pay for itself.

Think I'll cruise on up to Deep Homo tomorrow and price things out.

July 11, 2018, 05:21 PM

PHPaul

quote:
Originally posted by arcwelder76:
You could run PVC without issue, many shops I've worked in have used it. It'll cut down on condensation issues.

I don't think pex/sharkbite would be a problem for air pressure, given the limits of a typical non-industrial compressor.

Thanks, that's very reassuring.

July 11, 2018, 05:27 PM

smlsig

quote:
Originally posted by arcwelder76:
You could run PVC without issue, many shops I've worked in have used it. It'll cut down on condensation issues.

I don't think pex/sharkbite would be a problem for air pressure, given the limits of a typical non-industrial compressor.

Arc would you suggest Schedule 80 or do you think the regular Schedule 40 will do the trick?

July 11, 2018, 05:35 PM

arcwelder

quote:
Originally posted by smlsig:
quote:
Originally posted by arcwelder76:
You could run PVC without issue, many shops I've worked in have used it. It'll cut down on condensation issues.

I don't think pex/sharkbite would be a problem for air pressure, given the limits of a typical non-industrial compressor.

Downstream of the compressor, set to 100-120psi, I don't think you'll have a problem with sch40, but then, I didn't look for markings.

At least one condensate trap is in order, by the by.

Arc would you suggest Schedule 80 or do you think the regular Schedule 40 will do the trick?

July 11, 2018, 05:47 PM

9mmnut

Sharkbites are too expensive. Pickup some regular air line hose and a few fittings.

July 11, 2018, 05:52 PM

ffips

quote:
Originally posted by PHPaul:
quote:
Originally posted by ffips:
The cost of shark bite fittings vs pex fittings and a single hand pinch crimp tool might be similar if many fittings are needed.

I could ship you the crimp tool if you return it when done. Tool I have.

Heck, that's cheap enough. If I need more than a couple of fittings, it'll pay for itself.

Think I'll cruise on up to Deep Homo tomorrow and price things out.

That's why I have it. Tool plus fittings was better than hassle and downtime of RV.

July 11, 2018, 07:00 PM

JasonATI

What diameter of pipe, for schedule 40 1/2" is around 600psi and 3/4" is 480psi.

July 11, 2018, 09:43 PM

Sportshooter

quote:
Originally posted by arcwelder76:
You could run PVC without issue, many shops I've worked in have used it. It'll cut down on condensation issues.

I don't think pex/sharkbite would be a problem for air pressure, given the limits of a typical non-industrial compressor.

We used schedule 80 PVC with industrial screw compressors around the plant we placed pipe, regulators, moisture traps and oilers in the building purlins about head high to shield the PVC. It doesn’t like being knocked around by forklifts and such. We never had a problem or accident. In fact, I use PVC for the trunk lines in my shop.

July 11, 2018, 11:26 PM

Sailor1911

PHP: I did the very same thing and have operated it without issue for 25 years.

I ran 3/4 inch Schedule 40 PVC. At my compressor in the garage, I have a short air hose connecting the compressors regulator to the PVC line. PVC line has a T in it with one short run on the garage wall and the other long run down to the basement. That way I have air in the garage and the basement simultaneously. At the end of the PVC run in the basement, I have another regulator that I can use to run at the compressors regulated level (high) or I can crank it down to use the air brush.

Only cautionary note is, I generally don't just crank open the valve on the compressor and instantly charge the PVC lines. Instead, I just open it slowly to fill the line. Probably just paranoia but my fear has been blowing up the PVC or a connector so slow open is the rule for me anyway.

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July 12, 2018, 07:22 AM

MaSigchist

Pex is a good way to go. It's your home shop and you can do what you want, but OSHA considers it a hazard and does not allow PVC for compressed air ( LINK ). I know it is done all the time, but When PVC ruptures the shards can fly.

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July 12, 2018, 07:59 AM

Bluecobra

Helped a friend run Pex out to his detached garage about 4 years ago, from his compressor in a storage room. All we used was Pex and Sharkbite fittings. He keeps his regulator at 120 psi and has had no problems so far. Pex was much easier to deal with that PVC and seems more durable.

July 12, 2018, 03:18 PM

PHPaul

After considering pressures and volumes required and pricing everything out, I decided to go with 3/8 polyethylene tubing and plastic PEX fittings.

100 feet of tubing, all the fittings, clamps to tack the tubing to the beams, and two water separators - enough to do two drops in the basement, one by the machines, one in the hobby room for the airbrush - came to just under $100.

I did decide to add an additional regulator to the drop in the hobby room as I may need to adjust pressures for the airbrush and it'll save running up to the mudroom every time. Need to get some pieces-parts for that.

I fabbed up a bulkhead fitting over the basement door so I can put the compressor out in the mudroom and still keep the basement door closed for the heat in the winter.