Carl F. Baker
# 2012 Barcelona
The performance requirements for flexible polyolefin potable water piping systems in North America are quite different than those in other areas of the world. PolyEthylene – Raised Temperature (PE-RT) products were developed in Western Europe in the early 1980’s and since that time have evolved into the high performance products in use today as defined in the International Standards Organization (ISO) standards.
Many countries have adopted the ISO standards for PE-RT products around the world but in the United States the American Society of Testing and Materials (ASTM) standards are utilized. Canada uses the Canadian Standards Association (CSA) standards which closely mirror the ASTM standards. A CSA standard is in development but currently there is no CSA standard for PE-RT products. An ASTM standard for PE-RT potable water plumbing applications was introduced in 2009 as ASTM F2769. The performance requirements for PE-RT in ASTM F2769 are the same as those found in ASTM F876 for Crosslinked Polyethylene (PEX) tube.
In addition, the fittings standards specified for PEX tube are shared with PE-RT in most cases. ASTM F2769 has been incorporated into the 2012 version of the national building codes in the United States. The differences between the ISO and ASTM standards for PE-RT are quite extensive. One obvious difference is in tubing size where ISO standards utilize metric units and ASTM specifies English units and is based on Copper Tube Size (CTS). Another major difference is the oxidative stability requirement in the ASTM standard.
This requirement will be highlighted and discussed. There are other less obvious differences including hydrostatic ratings, slow crack growth resistance, fitting qualification, malfunction requirements, and others. Each of these will be discussed as it relates to product design.