1.1 本规范 2. 涵盖适用于腐蚀性或高温服务，或两者兼而有之，或适用于一般应用的电熔焊奥氏体铬镍不锈钢管。 注1: 无量纲指示符NPS（公称管道尺寸）在本标准中已被“公称直径”、“尺寸”和“公称尺寸”等传统术语所取代 1.2 本规范涵盖中列出的合金和不锈钢等级 表1 热处理的适当等级和要求的选择应由买方自行决定，具体取决于所遇到的使用条件。 1.3 包括以下五类管道: 1.3.1 1级-- 管道应通过在所有焊道中使用填充金属的工艺进行双面焊接，并应进行完全射线照相。 1.3.2 2级-- 管道应通过在所有焊道中使用填充金属的工艺进行双面焊接。 不需要射线照相。 1.3.3 3级-- 管道应通过在所有焊道中使用填充金属的工艺进行单焊，并应进行完全射线照相。 1.3.4 4级-- 与第3类相同，但暴露在管内表面的焊道可在不添加填充金属的情况下进行（参见 6.2.2.1 和 6.2.2.2 ). 1.3.5 5级-- 管道应通过在所有焊道中使用填充金属的工艺进行双面焊接，并应进行点射线照相。 1.4 提供了补充要求，涵盖了从额外测试到正式制造实践程序的各种规定。补充要求S1至S6包括在需要时指定的选项中。 1.5 以英寸磅单位或国际单位制表示的数值应单独视为标准。在正文中，国际单位制显示在括号中。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。将两个系统的值组合在一起可能会导致不符合规范。英寸磅单位应适用，除非订单中规定了本规范的“M”名称。 1.6 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 2 covers electric-fusion-welded austenitic chromium-nickel stainless steel pipe suitable for corrosive or high-temperature service, or both, or for general applications. Note 1: The dimensionless designator NPS (nominal pipe size) has been substituted in this standard for such traditional terms as “nominal diameter,” “size,” and “nominal size.” 1.2 This specification covers the grades of alloy and stainless steel listed in Table 1 . The selection of the proper grade and requirements for heat treatment shall be at the discretion of the purchaser, dependent on the service conditions to be encountered. 1.3 Five classes of pipe are covered as follows: 1.3.1 Class 1— Pipe shall be double welded by processes employing filler metal in all passes and shall be completely radiographed. 1.3.2 Class 2— Pipe shall be double welded by processes employing filler metal in all passes. No radiography is required. 1.3.3 Class 3— Pipe shall be single welded by processes employing filler metal in all passes and shall be completely radiographed. 1.3.4 Class 4— Same as Class 3 except that the weld pass exposed to the inside pipe surface may be made without the addition of filler metal (see 6.2.2.1 and 6.2.2.2 ). 1.3.5 Class 5— Pipe shall be double welded by processes employing filler metal in all passes and shall be spot radiographed. 1.4 Supplementary requirements covering provisions ranging from additional testing to formalized procedures for manufacturing practice are provided. Supplementary Requirements S1 through S6 are included as options to be specified when desired. 1.5 The values stated in either inch-pound units or SI 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 nonconformance with the specification. 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.