1.1 本规范涵盖了用于直埋和换衬应用的燃气总管和服务设施的聚酰胺12管道、管子和配件的特性要求和测试方法。本规范涵盖的管道和配件旨在用于天然气配送。 1.1.1 本规范涵盖的管道和配件不得使用锥形管螺纹连接。对接熔焊应按照惯例进行 F3372 . 中讨论了设计注意事项 附录X1 . 厂内质量控制计划见 附件A1 . 1.2 本规范的文本参考了提供解释材料的注释、脚注和附录。这些注释和脚注（不包括表和图中的注释和脚注）不应视为本规范的要求。 1.3 以英寸-磅为单位的数值应视为标准值。括号中给出的值是到国际单位制的数学转换，仅供参考，不被视为标准值。 1.4 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 注1: 采用热熔连接技术的管道和配件，由满足第3组2级和3级（PA323或PA11）要求的化合物制成，用于由满足第3组2级和3级要求的化合物制成的管道。 使用由满足第4组第2类和第3级（PA 423或PA12）要求的化合物制成的热熔连接技术的管道和配件，拟用于由满足第4组第2类和第3级要求的化合物制成的管道。根据各树脂制造商的建议，PA 323（PA11）和PA 423（PA12）化合物之间不允许交叉融合。 1.5 本国际标准是根据世界贸易组织技术性贸易壁垒（TBT）委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认标准化原则制定的。

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.