Heather & Joe Way wrote:
> Keith and others: Regardless of the rated pressure, PVC
> is *NOT* safe for use with air, and no manufacturer of
> PVC pipe or compressed air equipment will tell you
> otherwise.
I decided to do some research on this on my own today,
since I didn't see why PVC pipe would not be appropriate
for use with compressed air, and wanted to understand
what is going on, especially since it seemed like the
above claim had the potential for being urban legend,
or being for "traditional" PVC pipe, not Schedule 40 or
Schedule 80 PVC.
However, after reading what I can find on the net, it
seems like it would NOT be a good idea to use PVC for
air lines.
For engineers or the technically inclined, take a look
at Lasco Fittings WWW pages:
http://www.lascofittings.com/characte.htm
http://www.lascofittings.com/lascotit.htm
The first page above has a great chart contrasting
PVC pipe with steel pipe. It also explains that PVC
pipe doesn't handle surge pressures well. The second
page contains the big RED warning:
"Do not test PVC piping systems with compressed
air or gases."
My speculation is that the problems with PVC piping
being used with compressors is that there are probably
very high surge pressures, due to the extreme
compressibility of gases (contrasted with water), which
cause damage in PVC piping for air lines. Eventually,
the cumulative damage from repeated air surges will
cause a leak in the pipe. As to whether or not this
will cause a catastrophic failure is anybody's guess.
>From what I've read today, even though I'm no expert,
I would not use PVC Schedule 40 or even Schedule 80
for air compressor lines, until I found some manufacturer's
data to the contrary.
For more resources, see the following:
* http://www.plumbingsupply.com/pvc.html#faq
"Caution: Do not use these PVC fittings with compressed
air or gas systems."
--ken
--
Kenneth B. Streeter | EMAIL: streeter@sanders.com
Sanders, PTP2-A001 |
PO Box 868 | Voice: (603) 885-9604
Nashua, NH 03061 | Fax: (603) 885-0631
|