1.1 本规范涵盖适用于高强度变速箱服务管的锻造或轧制钢管法兰、锻造配件、阀门和零件。包括按照买方规定的尺寸或第节中引用的ASME或MSS尺寸标准订购的法兰、配件和类似零件 2. . 1.2 根据最低屈服强度要求，涵盖了几种等级的材料，如 表1 . 1.3 提供了补充要求。当补焊需要买方批准时，提供补充要求S1。 1.4 本规范以英寸-磅单位和国际单位表示。但是，除非订单规定了适用的“M”规格名称（国际单位制），否则材料应按英寸提供- 磅单位。 1.5 以国际单位或英寸-磅单位表示的数值应单独视为标准值。在文本中，SI单位显示在括号中。每个系统中所述的值并不完全相等；因此，每个系统必须独立于其他系统使用。结合两个系统的值可能会导致不符合标准。 1.6 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 forged or rolled steel pipe flanges, forged fittings, valves, and parts suitable for use with high-strength transmission-service pipe. Included are flanges, fittings, and similar parts ordered either to dimensions specified by the purchaser or to ASME or MSS dimensional standards referenced in Section 2 . 1.2 Several grades of material, based on minimum yield strength requirements, are covered, as indicated in Table 1 . 1.3 Supplementary Requirements are provided. Supplementary Requirement S1 is provided for use when purchaser approval is required for repair welding. 1.4 This specification is expressed in both inch-pound units and in SI units. However, unless the order specifies the applicable “M” specification designation (SI units), the material shall be furnished to inch-pound units. 1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. 1.6 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.