【国外标准】 Standard Specification for Polyamide 12 Gas Pressure Pipe, Tubing, and Fittings

This specification details the material and performance requirements, as well as the corresponding test methods, for the evaluation of polyamide 12 gas pressure pipes, tubing, and fittings that are intended for use in the distribution of natural gas in fuel gas mains and services for direct burial and reliner applications. It does not apply to threaded pipes. The pipes and fittings shall be made from virgin or reworked polyamide material that satisfies the short- and long-term hydrostatic design stress and hydrostatic design basis ratings, and rapid crack propagation (RCP) resistance properties. Properly sampled pipe and fitting specimens shall undergo test procedures and conform to the following requirements: workmanship; dimension (diameter, toe-in, wall thickness, wall thickness eccentricity range, ovality, and length); conditioning; slow crack growth resistance; resistance to RCP; minimum hydrostatic burst pressure/apparent tensile strength (quick burst); sustained pressure; outdoor storage stability; chemical resistance; elevated temperature service; butt fusion joints; butt heat fusion fittings; electrofusion fittings; mechanical fittings; transition fittings and anodeless risers; valves; and excess flow valves.1.1 This specification covers requirements and test methods for the characterization of polyamide 12 pipe, tubing, and fittings for use in fuel gas mains and services for direct burial and reliner applications. The pipe and fittings covered by this specification are intended for use in the distribution of natural gas.1.1.1 Pipe and fittings covered by this specification shall not be joined using taper pipe threads. Butt fusion joining shall be done in accordance with Practice F3372. Design considerations are discussed in Appendix X1. In-plant quality control programs are specified in Annex A1.1.2 The text of this specification references notes, footnotes, and appendixes which provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the specification.1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.NOTE 1: Pipe and fittings utilizing heat fusion joining techniques produced from compounds meeting the requirements of Group 3, Class 2, and Grade 3 (PA323 or PA11) are intended for use with pipe manufactured from compounds meeting the requirements of Group 3, class 2 and Grade 3. Pipe and fittings utilizing heat fusion joining techniques produced from compounds meeting the requirements of Group 4, Class 2 and Grade 3 (PA 423 or PA12) are intended for use with pipe manufactured from compounds meeting the requirements of Group 4, Class 2 and Grade 3. As per the recommendations of the respective resin manufacturers, no cross fusion between PA 323 (PA11) and PA 423 (PA12) compounds is permitted.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.