1.1 本规范涵盖高温承压件用球墨铸铁件。所有等级的铸件适用于450 华氏度。温度高于450 °F至650 °F，仅60-40-18级铸件适用( 注释1 ). 1.2 阀门、法兰、管件、泵和其他管道组件通常由制造商、批发商或经销商提前制造并现货供应。 1.3 补充铸件要求，规范 A834号机组 可以利用。 1.4 以国际单位或英寸-磅单位表示的数值应单独视为标准值。每个系统中规定的值可能不完全相等；因此，每个系统应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。 注1: 对于本节规定以外的服务，应参考规范 第536页 适用于球墨铸铁铸件。 2. 1.5 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 ductile iron castings for pressure-retaining parts for use at elevated temperatures. Castings of all grades are suitable for use up to 450 °F. For temperatures above 450 °F and up to 650 °F, only Grade 60-40-18 castings are suitable ( Note 1 ). 1.2 Valves, flanges, pipe fittings, pumps, and other piping components are generally manufactured in advance and supplied from stock by the manufacturer, jobber, or dealer. 1.3 For supplemental casting requirements, Specification A834 may be utilized. 1.4 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 nonconformance with the standard. Note 1: For service other than as specified in this section, reference should be made to Specification A536 for Ductile Iron Castings. 2 1.5 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.