scope:

The program undertaken by the PPI Task Group for the testing of representative materials under a set of conditions was designed to reflect the fusion conditions recommended for the butt fusion of PA-11 piping. Butt fusion evaluation work was performed starting in the mid-1990s by the Gas Research Institute¹ and continued at McElroy Manufacturing, Inc. and in the Arkema (formerly Atofina) R&D laboratories in Pennsylvania. The results of these studies, as detailed below, resulted in the recommended fusion procedures contained in Appendix A of this report. It is the intention that this procedure would be available for use by pipeline operators who would determine whether the procedure is appropriate for use with the PA-11 piping products it employs. Pipeline operators could consider the recommendations and testing performed by others in their effort to comply with the fusion procedure qualification requirements of 49 C.F.R. § 192.283 (Plastic pipe, qualifying joining procedures).

It is important to emphasize that the testing performed was intended only to establish a technical basis for developing and proposing a more generic fusion joining procedure that would offer the maximum opportunity to be qualified and used by pipeline operators. The testing was not intended to qualify the procedure for use with any PA-11 piping manufacturer's particular pipe product, and PPI offers no opinion on whether the procedure is properly qualified for use with any particular PA-11 piping. PA-11 pipe producers remain solely responsible for any representations that they may make about the use of this procedure or any other joining procedure with their proprietary PA-11 piping products, and pipeline operators remain solely responsible for compliance with the requirements of 49 C.F.R. § 192.283 (Plastic pipe, qualifying joining procedures) when qualifying any procedure for use with the products it selects for its pipelines. PPI member pipe manufacturers have endorsed this procedure for joining their product to itself and to other commercially available PA-11 pipe materials. Pipe producer compliance letters are in Appendix B for gas pipe applications. A typical illustration of a properly made PA-11 butt fusion joint is shown in Appendix C.

PPI believes that the inherent value of greater uniformity of this technical report will provide all the incentive necessary for companies to evaluate the procedure in Appendix A as a first option for butt fusion joining of its PA-11 piping products. Use of this procedure is obviously not mandatory, and every PA-11 pipe producer and pipeline operator retains the option of developing different procedures for its particular products and pipelines. However, PPI believes that its work in developing this procedure as a candidate for widespread acceptance throughout the industry will lead to greater efficiency, simplicity, and understanding in this area and promote the use of effective, qualified procedures for butt fusion joining of PA-11 pipe.

¹ H.V. Patadia, R.H. Doctor, "Final Report - Part I: Technical Reference on the Physical, Mechanical, and Chemical Properties of PA11 Pipe Materials for Use in Gas Distribution Systems Operating at Higher Pressures and Temperatures," GRI-99/0039, 55 (1998).