> In my opinion if the manufacturers DO NOT recommend PVC for high
> pressure air lines, then there must be a very good reason.
There are two, IMHO.
1. Economics
2. Liability
1. PVC pipe manufacturers are in the business to sell PVC pipe, for
which they have extensively developed, tested and documented their
pipe as suitable for the containment and distribution of water and
waste. It would involve major effort and expense for these
manufacturers to extensively test and document their product as
suitable for compressed air. They aren't going to be particularly
enthusiastic about doing this, since these manufacturers would
sell insignificant amounts of air line when compared to the
boat-loads of the stuff they sell as water line. The economics
don't weigh out. Too much expense to test and certify vs too little
payback in sales.
2. Residential water lines typically come in at around 100 PSI with
+/- 50PSI surges, so containment of pressure isn't an issue. What is
a significant issue however is the installation of the PVC line
itself. The plumbing contractor is a licensed, bonded and insured
installer of PVC, and this certification relieves the PVC
manufacturer of many liability concerns, since the plumber bears
some of the liability burden. The same would not be true of me going
into my garage and plumbing it in PVC airline. If I make a mistake
and misglue a joint and it blows, then a good shark-type product
liability lawyer can make me a very rich man at the expense of the
PVC manufacturer. That darn PVC manufacturer should have known
that I was incompetent and should have designed the product
better (No one ever said product liability lawsuits were fair).
Therein lies the rub. While PVC can and does make a reasonably safe
and serviceable air line when installed, used and maintained in a
reasonably safe and conscientious manner, the manufacturer is not
going to certify it as such without covering their wallets under
10-12' of very expensive testing results.
FWIW, I don't typically shoot guns in my auto shop either. But some
customers........;-)
Take care,
Greg Price
All XJs, 3134-C Rufina Street, Santa Fe, NM 87505
1-888-JAG-BITS FAX: 1-505-466-9315
NEW PARTS SPECIALS: http://www.rt66.com/~gprice/specials.html
|