A new standard has been released that evaluates the possible effects of chlorinated water on PEX (crosslinked polyethylene) piping. F 2023, Standard Test Method for Evaluating the Oxidative Resistance of PEX Thermoplastic Piping is available from the American Society for Testing and Materials (ASTM). Approved in June 2000, F 2023 was devised by a task group of ASTM Subcommittee F17.40 on Test Methods in Committee F17 on Plastic Piping Systems.

By performing the evaluation in F 2023, PEX suppliers can measure and compare various formulations and assess future modifications, said Task Group Chairman Stephen Pregun, a consultant with Pregun's Polymer Services, Houston, TX, and a 40-year plastics industry veteran formerly with Shell Chemical. "The results obtained from the test method will provide a reference index so that materials can be compared under similar, extremely aggressive test conditions that exceed those conditions typically found in U.S. plumbing systems," he noted.

"This standard was developed specifically to provide a method whereby pipe utilizing PEX could be evaluated under extremely aggressive conditions," Pregun added.

"The major use [for PEX piping] would be in potable water plumbing systems containing chlorine levels usually between 0.4 and 2.0 ppm of chlorine operating at temperatures of 150¯F or below. Another significant and long-established use is in underfloor heating applications where long lengths of pipe can be coiled, minimizing the need for joints," Pregun said, adding that PEX is also being considered for use in residential fire sprinkler systems.

ASTM standards are available by calling Customer Service at (610) 832-9585 or by e-mail at service@astm.org, or through the Web site Store (www.astm.org).