Shop related threads

[Dr Stan]

Can a shop related sub-forum be started?  I'm thinking of a place to discuss shop equipment (non-metal working), building, electrical, plumbing, modifying etc.

[Vinny]

Good idea.

[Vinny]

It's created!

[Mike E.]

I like this topic.

[Old Minger]

I'll kick it off.
So I want to put an air distribution system in my shop. I'm thinking of using 3/4" pex pipe to black iron fittings. Any thoughts?

[Vinny]

I created the shop forum, it's in Misc near the bottom of the main page.

[Dr Stan]

(11-29-2016, 10:49 PM)Old Minger Wrote: I'll kick it off.
So I want to put an air distribution system in my shop. I'm thinking of using 3/4" pex pipe to black iron fittings. Any thoughts?

I've taught fluid mechanics and at one point there were those who advocated using sch 80 PVC with threaded fittings.  However too many simply used glued fittings and/or sch 40.  It doesn't take much imagination to figure out how well that worked.  Not ! ! !

There are fittings especially made for the PEX so I would not recommend using CI fittings as a substitute.

It's not exactly inexpensive, but it has lots of advantages.  Cut it to length with a utility knife, install the fitting, crimp and you're done.  It also does not rust like CI.

[f350ca]

Did a quick look and the pressure rating for PEX is only 100 psi at 180 F. The air coming off the compressor can be lot hotter than that. Even cool its only rated at 160 psi at 74 F , not much of a safety factor.

[awemawson]

MDPE pipe is used here in the UK for underground water distribution, in a tasteful blue hue. I have used it for years as an air distribution system in several workshops with no problems at all. Where I I am at the moment I have literally hundreds of meters of it both internally and joining buildings underground.

A full range of fittings are available

[pepi]

Not wanting to find out myself for sure, but....
Years ago I had PVC type air system 200psi plumbed, about 30 feet. After reading and digesting veracious papers regarding the potential for the material to become brittle.  And pointing out the reason was the expansion and contraction cycles created as the air pressure fluctuates. Yes the material was rated beyond the system pressure. Loads of specs in the world meant to sell product, in the end common sense must prevail.

When I move the compressor outside, reinstalled piping with galvz. Just seems like a sounder way of going about it.
Just saying,
Greg