I am going to fit a 14mtr long compressed air pipe around my new workshop. It will have x3 outlet couplings via the usual regulator, traps and filters etc. What I would like your opinion on is, as I am in the building trade and have access to cheap copper tube, will 22mm copper tube be suitable, and regards to fittings, soldered or compression?

what pressure do you intend running it at? and what flow might you want?

edit I would put pressure regulators at the outlets as well as regulating the overall pressure

[Edited on 1/3/16 by gremlin1234]

I've used 15mm for about 2m to two regulators, one for tools the other for the spray gun.

copper with solder or comp fittings will be fine, mine has been in for nearly 20 years

The spec sheet for Yorkshire Copper rates 22mm half hard tube at 51 bar at 65deg C, plenty.

I used 15mm copper with soldered and compression fittings and it's fine. I would stick to 15mm rather than 22mm just to reduce the condensate in the air.

For that length I used Hep20x22mm. Condensation is much better (less) with plastic pipe. It can take the pressure no problem.

Thanks for the answers, copper it is then, that's great.

With regards to the suggestion of "theprisoner" and plastic, I was advised to avoid it, this is due to over a period of time the oils etc in the compressed air will lead to the degradation of the pipe and it becoming brittle. Which may lead to it exploding and sending out dangerous razor sharp fragments. Be careful mate.

Once again thanks for the replies.

HDPE is the material of choice in my laboratory to carry air (and other) gases, it has the major advantage that it doesn't corrode. It's inert to just about everything, I mean, it's polyethylene. It will degrade, it will (just) about dissolve in hot hydrocarbons, but I suspect you'll be in the care home before it's an issue. As for the O-ring seals that the joints often rely on... hmmm...

Copper is used around the external compressors, these drive nitrogen generators, copper (15mm, 22mm and 28mm) is used, without issue. Compression and soldered joints everywhere, surviving harsh conditions, no problems. It does tend to corrode, externally and internally, but again, it's not a monument.

So... take your choice, both will be OK.

Avoid galvanised steel, black iron and PVC (especially the latter, since it will degrade with unwanted consequences)

I have a book on my shelf regarding air tools - they suggest copper tube, but make sure there's a slight angle down to the compressor (1" every 12' ) and put a short down-tube near the compressor end with a drain valve on it. If it's a long run then put a drain valve at both ends.


[Edited on 2/3/16 by David Jenkins]

Pretty sure John Guest do a range of push fit plastic specifically designed for compressed air.

quote:

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Originally posted by Wadders
Pretty sure John Guest do a range of push fit plastic specifically designed for compressed air.

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Thanks again everybody.

John Guest - http://www.johnguest.com/products/air-and-pneumatics/air/

I second the use of nylon pneumatic tubing, with push fit tees & joiners.

i.e. eBay Item

I used to work in the chemical industry (solvent recovery) and all plant control systems ran using nylon.
Some of the ducting valves you could stand up in, ran on 12mm nylon pipes to the ram.


My workshop has a compressor, auxiliary tank, a manifold around the roof, with drop down plug in points
for airlines, all in push fit nylon.


Paul G



[Edited on 3/3/16 by 907]