||New Test Method Provides Solid Evaluation of PEX Plumbing
A new standard 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 now available from ASTM. Approved
in June, F 2023 was devised by a task group of 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,
says Task Group Chairman Stephen Pregun, a consultant with Preguns
Polymer Services, Houston, Texas, 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 notes.
Over the past 20 years there has been considerable debate over
the suitability of plastic pipe for use in potable water plumbing
systems, he explains. In particular the long term performance
of polyolefin piping was questioned. This standard was developed
specifically to provide a method whereby pipe utilizing PEX could
be evaluated under extremely aggressive conditions.
PEX piping is currently most widely used in a variety of water
applications in North America, Europe, and Asia, continues Pregun,
who has developed plastic piping standards with ASTM for 35 years.
The major use would be in potable water plumbing systems containing
chlorine levels usually between 0.4 and 2.0 parts per million
of chlorine operating at temperatures of 150 degrees 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.
PEX is also being considered for use in residential fire-sprinkler
Technical questions may be directed to Stephen Pregun, Preguns Polymer Services, 5711 Sugar Hill #39, Houston, TX
77057(phone/fax: 713/ 782-2898). Committee F17 meets Nov. 13-16
in Orlando, Fla. For meeting or membership information, contact
Staff Manager Pat Picariello, ASTM (610/832-9720). //
Copyright 2000, ASTM