1.1 本规范 2. 包括碳钢管和合金钢管，电熔焊，添加填充金属，由具有多种分析和强度等级的压力容器质量板制成，适用于高温高压环境。为了达到所需的机械性能或符合适用的规范要求，可能需要或不需要热处理。当需要额外的测试或检查时，提供了补充要求。 1.2 该规范名义上涵盖16英寸的管道。外径为[400 mm]或更大，壁厚可达3英寸。 [75毫米]包括在内。可提供其他尺寸的管道，前提是其符合本规范的所有其他要求。 1.3 提供了几种等级和类别的管道。 1.3.1 等级 指定中列出的板类型 表1 . 1.3.2 班 指定在管道制造过程中进行的热处理类型，是否对焊缝进行了射线照相检查，以及管道是否已按表1所列进行了压力测试 1.3.3 . 1.3.3 类别名称如下( 注1 ): 班 管道热处理 射线照相，见第节 压力测试，见第节 10 没有一个 没有一个 没有一个 11 没有一个 9 没有一个 12 没有一个 9 8.3 13 没有一个 没有一个 8.3 20 应力消除，参见 5.3.1 没有一个 没有一个 21 应力消除，参见 5.3.1 9 没有一个 22 应力消除，参见 5.3.1 9 8.3 23 应力消除，参见 5.3.1 没有一个 8.3 30 归一化，请参见 5.3.2 没有一个 没有一个 31 归一化，请参见 5.3.2 9 没有一个 32 归一化，请参见 5.3.2 9 8.3 33 归一化，请参见 5.3.2 没有一个 8.3 40 正火和回火，见 5.3.3 没有一个 没有一个 41 正火和回火，见 5.3.3 9 没有一个 42 正火和回火，见 5.3.3 9 8.3 43 正火和回火，见 5.3.3 没有一个 8.3 50 淬火和回火，参见 5.3.4 没有一个 没有一个 51 淬火和回火，参见 5.3.4 9 没有一个 52 淬火和回火，参见 5.3.4 9 8.3 53 淬火和回火，参见 5.3.4 没有一个 8.3 注1: 材料的选择应注意使用温度。对于此类指导，规范 A20/A20M 可咨询。 1.4 提供了补充性的可选要求，要求在需要时对补焊进行额外测试和控制。 1.5 以国际单位制或英寸-磅单位表示的数值应单独视为标准值。在文本中，国际单位显示在括号中。 每个系统中规定的值可能不是精确的等效值；因此，每个系统应相互独立使用。将两个系统的值合并可能会导致不符合标准。除非订单中规定了本规范的“M”名称，否则英寸-磅单位应适用。 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 2 covers carbon and alloy steel pipe, electric-fusion-welded with filler metal added, fabricated from pressure-vessel-quality plate of several analyses and strength levels and suitable for high-pressure service at high temperatures. Heat treatment may or may not be required to attain the desired mechanical properties or to comply with applicable code requirements. Supplementary requirements are provided for use when additional testing or examination is desired. 1.2 The specification nominally covers pipe 16 in. [400 mm] in outside diameter and larger with wall thicknesses up to 3 in. [75 mm] inclusive. Pipe having other dimensions may be furnished provided it complies with all other requirements of this specification. 1.3 Several grades and classes of pipe are provided. 1.3.1 Grade designates the type of plate used as listed in Table 1 . 1.3.2 Class designates the type of heat treatment performed in the manufacture of the pipe, whether the weld is radiographically examined, and whether the pipe has been pressure tested as listed in 1.3.3 . 1.3.3 Class designations are as follows ( Note 1 ): Class Heat Treatment on Pipe Radiography, see Section Pressure Test, see Section 10 none none none 11 none 9 none 12 none 9 8.3 13 none none 8.3 20 stress relieved, see 5.3.1 none none 21 stress relieved, see 5.3.1 9 none 22 stress relieved, see 5.3.1 9 8.3 23 stress relieved, see 5.3.1 none 8.3 30 normalized, see 5.3.2 none none 31 normalized, see 5.3.2 9 none 32 normalized, see 5.3.2 9 8.3 33 normalized, see 5.3.2 none 8.3 40 normalized and tempered, see 5.3.3 none none 41 normalized and tempered, see 5.3.3 9 none 42 normalized and tempered, see 5.3.3 9 8.3 43 normalized and tempered, see 5.3.3 none 8.3 50 quenched and tempered, see 5.3.4 none none 51 quenched and tempered, see 5.3.4 9 none 52 quenched and tempered, see 5.3.4 9 8.3 53 quenched and tempered, see 5.3.4 none 8.3 Note 1: Selection of materials should be made with attention to temperature of service. For such guidance, Specification A20/A20M may be consulted. 1.4 Optional requirements of a supplementary nature are provided, calling for additional tests and control of repair welding, when desired. 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 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. The inch-pound units shall apply unless the “M” designation of this specification is specified in the order. 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.