1.1 本规范涵盖与NPS钢管一起使用的黑色或镀锌焊接或无缝螺纹钢联轴器 1. / 8. 至NPS 20[DN 6至DN500]，包括( 注1 )。根据本规范订购的联轴器适用于参考本规范的管道规范中列出的用途。 注1: 无量纲指示符NPS（公称管道尺寸）和DN（公称直径）在本标准中已被替换为公称直径、尺寸和公称尺寸等传统术语。 1.2 以国际单位制或英寸表示的数值- 磅单位应单独视为标准单位。每个系统中规定的值可能不是完全相等的；因此，每个系统应独立使用。将两个系统的值合并可能导致不符合标准。 1.3 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。

1.1 This specification covers black or galvanized welded or seamless threaded steel couplings for use with steel pipe in NPS 1 / 8 to NPS 20 [DN 6 to DN 500] inclusive ( Note 1 ). Couplings ordered under this specification are intended for the uses outlined in the pipe specifications referencing this specification. Note 1: The dimensionless designator NPS (nominal pipe size) and DN [diameter nominal] has been substituted in this standard for such traditional terms as nominal diameter, size, and nominal size. 1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard. 1.3 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.