1.1 本规范包括预制风管组系统的制造要求和安装指南，包括封闭在混凝土外壳中的聚氯乙烯（PVC）风管。本规范还包括与挖沟、回填、堵塞以及完整安装所需的其他杂费有关的信息。 1.2 以英寸磅为单位的数值应视为标准。括号中给出的值是国际单位制的数学转换，仅供参考，不被视为标准。 1.3 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 includes the manufacturing requirements and installation guidelines of a precast duct bank system including polyvinyl chloride (PVC) duct enclosed in a concrete envelope. This specification also includes information relating to trenching, backfilling, plugging, and other incidentals necessary for a complete installation. 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.