dpb wrote:
Hoosierpopi wrote:
...
I'm sure there are stats and such to back this up, but personal
experience says "bunk."

Below link outlines the issue and at least one alternative--

http://www.hydraulicspneumatics.com/...lse/6547/Issue

Here's the link to and an excerpt from the OSHA (I think original on
the subject) announcement--

http://www.nmsu.edu/~safety/news/new..._air_lines.htm

...
MEMORANDUM FOR REGIONAL ADMINISTRATORS
...
FROM: EDWARD BAIER
Director
Directorate of Technical Support

SUBJECT: Safety Hazard Information Bulletin on
the Use of Polyvinyl Chloride (PVC) Pipe
in Above ground Installations

The Dallas Regional Office has brought to our attention a potential
serious hazard existing with the use of polyvinyl chloride (PVC)
plastic pipes for transporting compressed gases in above ground
installations. An employee in a Texas plant was injured recently by
a
rupture in a PVC compressed air line. Plastic projectiles from the
point of rupture caused lacerations of the employee's hand. This is
noteworthy because the Plastic Pipe Institute, in its Recommendation
B dated January 19, 1972, recommends against the use of
thermoplastic
pipe to transport compressed air or other compressed gases in
exposed
plant piping. ...

Furthermore, sections 842.32, 842.43 and 849.52(b) of the American
National Standards Institute/American Society of Mechanical
Engineers
(ANSI/ASME) B31.8-1986, Gas Transmission and Distribution Piping
Systems Standard, limit the operating pressure of plastic piping
distribution systems to 100 pounds per inch (psi) and prohibit the
installation of such systems above ground except where ". . . the
above ground portion of the plastic service line is completely
enclosed in a conduit or casing of sufficient strength to provide
protection from external damage and deterioration."

...
We used a big old eighty-gallon unit with a 5HP motor and
heavy-duty
two-stage compressor we got from a body shop that closed down.

Size/HP of the compressor aren't the issue nearly as much as the
operating pressure and to a somewhat lesser degree the piping sizing
(larger diameter -- more schrapnel in case of fracture). The OSHA
mandate is for 100 psi systems I believe.


We're talking nearly ten years of use w/o issues and moved the
system
to a new warehouse where its been doing nicely for seven more
years.

Regarding a specific system and experience, it's only an issue when
it
becomes one; unfortunately when that happens it could cause a
significant injury.

It's one of those things where I'm not going to tell anybody they
have
to do something but it is imo irresponsible to recommend it.

It's kind of like running into someone who rides a motorcycle and says
"I've never crashed so why wear a helmet?".

--
--
--John
to email, dial "usenet" and validate
(was jclarke at eye bee em dot net)