Richard Wolf, Koji Nakamura
Papers # 2010 Vancouver
In 2004 a project was initiated by UBE Industries, Ltd. to evaluate the feasibility for use of polyamide 12 in natural gas distribution systems in the United States. The objective of the project was to develop a polyamide 12 natural gas distribution system capable of operating at pressures greater than that imposed by current restrictions and at temperatures above those achieved by commercially available thermoplastic systems. US regulatory restrictions limit the use of thermoplastic systems to a maximum operating pressure of 125 psig. As the project progressed, the scope was expanded to include global activities. The project was broken into two distinct phases. Phase 1 from February 2004 to December 2006 included a comprehensive laboratory evaluation and limited field service use to determine the feasibility for use of polyamide 12 natural gas distribution systems operating at pressures greater than 125 psig and elevated temperatures. Long term strength performance, slow crack growth and rapid crack propagation characteristics, the effect of secondary stresses along with extensive testing to accepted industry test methods were evaluated. Studies were conducted to develop a full set of installation, maintenance and operating procedures for the use of polyamide 12 systems. Additionally, several small scale private property installations took place as part of the Phase 1 project. Based on the positive results from laboratory and field evaluations of polyamide 12 systems, a Phase 2 project was developed. The objective of the Phase 2 project was to commercialize the use of polyamide 12 systems for use at pressures greater than 125 psig. During this phase of the project, installations are being performed with utilities in North America within their respective operating areas. These installations are being performed under special permits in cooperation with the respective state and federal regulatory bodies. As a separate activity, samples have been removed from the trial installations at specific time intervals and characterized for retention of physical and mechanical properties. The sample removal and evaluation study is an ongoing activity. The paper presents an overview of the laboratory analysis and field installation activities performed in the Polyamide 12 gas distribution systems project. The data is presented in the context of compliance to the active ASTM polyamide 12 standards.