[TheForge] PVC for compressed air

[Dave Mudge]

The "CYA" clause in my personal safety first and don't get sued book dictates
that I say "I AM NOT RECOMMENDING THIS".....
I have a medium size air compressor that puts out around 20 cfm @ 125 lb/sq.in.
It sits atop an 80 gallon tank which is then piped into a 150 gallon tank.
I use sch. 40, 1-1/2" pvc that runs up the wall and around the shop in a loop.
The 1-1/2" "T's" off and runs to within a foot or so of the air hammer
where it reduces to 3/4"
and then feeds the controls of the hammer. I also "T" off and run down the wall
to shoulder height, reduce to 1/2", and through fittings and such to 3/8" rubber
or plastic air line for regular shop use. I used this system for 10 or 15 years
before the hurricane and have re-established the system since rebuilding.
It has not failed so far (thank the gods). My system stays charged 24/7.
I never turn off the compressor. I don't have any leaks so I don't worry about
the compressor constantly running when I am not using any air. My system is not
flexing very much. What will disintegrate pvc is direct sunlight. If
you use pvc and
it is exposed to direct sunlight, you should paint the part in the
sun. The paint of course
will protect the pvc from the sun. I DO NOT RECOMMEND THAT ANYONE USE PVC
FOR THEIR SHOP AIR SYSTEM.
be safe,
dave m

On Tue, Apr 5, 2011 at 8:15 AM, David E. Smucker
<davesmucker at hotmail.com> wrote:
>
> If you use PVC for compressed air it will fail -- the only question is when
> and how.  Not only is fatigue an issue but oil from the compressor may also
> effect the PVC.
>
> There is plastic pipe compounded and design for air system piping -- but you
> will need to go to a major plastic pipe supply, or one that sells systems
> for shop use to find it -- not your local Big Box store.
>
> Here is one supplier  http://www.rapidairproducts.com/  they sell both nylon
> tubing and a composite plastic and aluminum pipe and the required fittings.
> This is just one source -- other can be found by google on "compressed air
> piping"
>
> Dave
>
> --------------------------------------------------
> From: "Paul N" <crosspein at sbcglobal.net>
> Sent: Tuesday, April 05, 2011 8:33 AM
> To: "Blacksmithing List Sponsored by ABANA" <theforge at mailman.qth.net>
> Subject: Re: [TheForge] PVC for compressed air (A little OT -- a mini-scale
> saber saw?)
>
> > I'd be cautious about using PVC for compressed air. For years, there
> > have been debates about the danger, and I pretty much disregarded them.
> > Then about 10 years ago, I gave in and decided to replace it with type
> > "L" copper. Type L is what is recommended for compressed air. Many of
> > the big box stores carry it, in addition to the cheaper Type "M", which
> > is what is used for the most common plumbing.
> >
> > The danger of PVC is similar to what is currently in the news for the
> > Boeing 737's. The constant flexing from the pressurization and
> > depressurization work hardens it over timee and makes it brittle. Then
> > it cracks and fails catastrophically, often sending plastic shrapnel in
> > all directions.
> >
> > I became a true believer as I removed the sched. 40 PVC I had previously
> > installed. It had been "in service" for about 7 years, and when I pulled
> > those pieces down, a number of sections cracked and shattered. They were
> > no longer the pliable pipes that they were when I installed them. So,
> > unless your plumbing is underground, I'd be very wary of using PVC for
> > compressed air.
> >
> > **paul
> >
> > On 4/5/11 1:07 AM, peter fels wrote:
> >> How much air do you need?
> >> More storage means more air for longer.
> >> Be very conservative with air pressure tanks!
> >> They can go off like a bomb!..Lotta kinetic energy!
> >> Putting them somewhere way over there, has a lot of virtue.
> >>
> >> My first compressor was from an old refrigeration unit,
> >> The tubing went to 2, 250 gallon, ( carefully washed out) former propane
> >> tanks.
> >> I used several hot water heater over- pressure valves in each one and
> >> tapped a hole in the bottoms
> >> for radiator drain valves .
> >> Ordinary sched 40 house plumbing will generally deal with 100 PSI. if you
> >> are careful.
> >>
> >> It was enough air to do a little sandblasting...or run an air tool for a
> >> while.
> >> Needless to say, that rig took a long time to recover.
> >> Safe from air tool boredom.
> >> Cost around $5 for fittings i couldn't scrounge.
> >>
> >> On Apr 4, 2011, at 8:49 PM, Bruce Freeman wrote:
> >>
> >>> How big a tank do you mean?
> >>>
> >>> On Mon, Apr 4, 2011 at 6:59 PM, peter fels<artgawk at thegrid.net>  wrote:
> >>>> An inexpensive little compressor ( even one from a bigger freezer) and
> >>>> a big pressure rated storage tank,
> >>>> will cover a whole lot of applications.
> >>>>
> >>>...
> > <snip>
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