[TheForge] PVC for compressed air (A little OT -- a mini-scale saber saw?)

[Paul N]

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.
>>>
>>...
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