Personally,
I'm not worried about the pressure rating on PVC. What happens when your
air system pressure is up, and you knock over that piece of bar stock, or
even a 2x4 and it smacks that plastic. My guess is you'll be missing about
2 feet of PVC, the air that was in it, and will have destroyed EVERYTHING in
the vicinity. Ever heard of a pipe bomb? My choice would be copper!
P.S. Keep in mind - the bigger the pipe, the bigger the bomb....
Sheldon Schmidt
SS Machine Works, Inc.
'55 3100
'56 3100 NAPCO
-----Original Message-----
From: owner-oletrucks@autox.team.net
[mailto:owner-oletrucks@autox.team.net]On Behalf Of Miq Millman
Sent: Thursday, December 13, 2001 10:52 PM
To: jrdorsey@strato.net
Cc: oletrucks@autox.team.net
Subject: Re: [oletrucks] compressed air hell and back again
john dorsey says:
>
> Schedule 40 pvc pipe in the sizes (1/2"-3/4") used for home shop air is
> rated at over 400 psi.
>
> If I were piping for air I would use Schedule 80 which is twice as thick
> as schedule 40 and can handle much more pressure.
>
> Now I am NOT recomending using PVC, I am just saying that the RIGHT pipe
> if not defective, PROPERLY installed will handle the pressures of a home
> shop air system.
I disagree. You are wrong and if anyone does this they are living with a
time bomb in their shop. See below.
> Note I say "if not defective". I say this because I am seeing more and
> more products that are not made well. Before you use any "Life-Safety"
> issue product, inspect it. Even black pipe will blow if it has a bad
Black pipe will not shatter under pressure, it will leak air,
>
> One big caveat about PVC, it hates heat, so don't tie it directly to the
> compressor or use it where it will be exposed to more than room
> temperature. I have seen where plumbers have tied it to the cold inlet
It doesn't matter whether the PVC pipe is schedule 40, 80, or even 120. it
is not the thickness of the long runs of pipe that is the issue.
READ THIS:
The problem is the connections used to make T or elbows for PVC is not
rated. The construction of a typical T causes the plastic to have extreme
variation in wall thickness. This variation will cause stress fractures.
When the compressor shuts off or starts up there can be spikes of pressure
much greater than the 125 or even 400 psi. Especially around connections.
Think about this for a second: if you aren't worried about your eyesight,
what about the paint job you just spent untold thousands of dollars or
hours working on,
--
__
Miq Millman miq@bigllama.com
Tualatin, OR Big Llama Productions
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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