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OSHA says PVC pipe is not acceptable for transporting compressed air, as it could burst under these pressures. OSHA says employers should only use piping rated by the manufacturer for the specific application.
In an OSHA citation dated 4/17/2014, the agency states that “Among other methods, feasible and acceptable methods include:
“a. Not using PVC pipe under pressure. According to the Plastic Pipe Institute and the Plastic Pipe and Fittings Association, “PVC piping does not possess shatter-resistant properties, and failure of the piping presents a serious hazard to employees from resultant flying shards or pipe fragments which become rapidly propelled by the released energy of a suddenly decompressing gas.” ASME B31.3, A323.4.2 states “PVC and CPVC shall not be used in compressed air or other compressed gas services,” or ASME B31.9 paragraph 923.3.2 states “PVC, CPVC and PVDF, which exhibit brittle failures as determined by ASTM F412, shall not be used for compressed air or gas service.””
“b. Replacing PVC piping and fittings with piping and fittings designed to be used under pressure such as metal piping and fittings, which are rated to transport compressed air in exposed above-ground locations or PVC piping and fittings with Acrylonitrile-Butadiene Styrene (ABS) pipes and fittings, which are shatter-resistant and manufactured for above-ground use of compressed air.
“c. Following the guidelines in 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 that state, 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.””