1.1 本规范涵盖了以下标准钢管尺寸的黑色和镀锌（热浸镀锌）焊接和无缝碳钢管接头以及焊接和无缝奥氏体不锈钢管接头的要求 1. / 8. 至12英寸。包括标准长度或特殊长度。 1.1.1 焊接碳钢- 根据这些要求订购的管接头用于规范中描述的一般用途 A53/A53M型 或规范所述的低温应用 A333/A333M飞机 . 1.1.2 无缝碳钢- 根据这些要求订购的管接头适用于通用和特殊用途，如适用规范所述 A53/A53M型 和 A106/A106M型 或规范所述的低温应用 A333/A333M飞机 （请参见 4.1.1 ). 1.1.3 奥氏体不锈钢- 根据这些要求订购的管接头适用于规范所述的高温和一般腐蚀环境 A312/A312M飞机 （请参见 4.1.2 ). 1.1.4 本规范的文本包含注释或脚注，或两者都包含，提供解释性材料。此类注释和脚注（表格中的注释除外）不包含任何强制性语言。 1.2 以英寸-磅单位表示的数值视为标准值。括号中给出的值是数学转换为SI单位，仅供参考，不被视为标准单位。 1.3 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 the requirements for welded and seamless carbon steel pipe nipples, black and zinc-coated (hot-dip galvanized), and welded and seamless austenitic stainless steel pipe nipples in standard steel pipe sizes from 1 / 8 to 12 in. inclusive, in standard or special lengths. 1.1.1 Welded Carbon Steel— Pipe nipples ordered under these requirements are intended for general uses, as described by Specification A53/A53M or for low-temperature service as described by Specification A333/A333M . 1.1.2 Seamless Carbon Steel— Pipe nipples ordered under these requirements are intended for general and special uses, as described by the applicable Specifications A53/A53M and A106/A106M or for low temperature service as described by Specification A333/A333M (see 4.1.1 ). 1.1.3 Austenitic Stainless Steel— Pipe nipples ordered under these requirements are intended for high-temperature and general corrosion service, as described by Specification A312/A312M (see 4.1.2 ). 1.1.4 The text for this specification contains notes or footnotes, or both, that provide explanatory material. Such notes and footnotes, excluding those in tables, do not contain any mandatory language. 1.2 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. 1.3 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.