In article ,
Smitty Two wrote:
In article ,
"Ed Pawlowski" wrote:

PVC is not allowed for air use.

If that's true, there's a few thousand machine shops who are breaking
some sort of rule. It's more or less the standard.

This was copied directly from the OSHA web site, it is one of the
first hits from searching google for "PVC compressed air OSHA regulation"

BEGIN QUOTE:

February 28, 1991

MEMORANDUM FOR: R. DAVIS LAYNE
Regional Administrator

FROM: PATRICIA K. CLARK, Director
[Directorate of Enforcement Programs]

SUBJECT: Use of Thermoplastic Pipe in Above Ground Locations



This is in response to your memorandum of January 17, concerning a recently
issued [Safety and Health Information Bulletin (SHIB)] dated December 13,
1990, by the [Directorate of Science, Technology and Medicine]. The SHIB
was issued in connection with the use of thermoplastic pipes in above ground
transportation of compressed air or gases, and was based on the Plastic
Pipe Institute's recommendation, dated December 1, 1989.

You indicated in your memorandum that various companies in your Region
are misinterpreting the SHIB to imply that regular polyvinyl chloride
(PVC) pipes that are designed to meet American Society for Testing and
Materials (ASTM) Standard D1785-86, can be used for transportation of
compressed air and gases. The SHIB, however, means that the pipes must
either be constructed of or be encased in shatter resistant materials.

You requested an official citation issuance policy regarding the use of
PVC pipes for above ground transportation of compressed air or gases.
You also requested our office to describe a citation scenario.

Since PVC material does not possess shatter resistant property, and since
it is very clear from the industry's recognized practice that PVC pipes
are prohibited for above ground transportation of compressed air and
gases (unless the pipelines are encased in shatter resistant material),
any such use by the employers, where employees may be exposed to hazards,
will be in violation of Section 5(a)(1) of the OSH Act. Therefore,
employers who are found to violate the above described conditions or
manufacturer's recommendations, during an OSHA inspection, shall be
issued a 5(a)(1) citation.

For any further clarifications, please have your staff members contact
[the Office of General Industry Enforcement at 202-693-1850].


END QUOTE


It is not difficult to find cases of actual injuries caused by shattered
PVC pipe. Note that there are certain plastic pipe materials specifically
approved for use with compressed air. Some of them may even contain PVC.
But common PVC plumbing pipe is not one of those.

--
There is always an easy solution to every human problem -- neat,
plausible, and wrong." (H L Mencken)

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar. org