1.1 本规范涵盖了屏蔽过渡管接头的性能，以连接地面以上15英寸（含15英寸）的不同DWV管道和配件。管道和配件。本标准旨在涵盖用于连接不同尺寸、材料和不同外径的管道和管件的异径管接头。 1.2 以英寸-磅为单位的数值应视为标准值。括号中给出的值是到国际单位制的数学转换，仅供参考，不被视为标准值。 1.3 对本标准具有管辖权的委员会不知道其他组织发布的任何类似标准。 1.4 以下预防意见仅适用于试验方法部分第节 7. ，符合本规范。 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全、健康和环境实践，并确定监管限制的适用性。 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 the performance of shielded transition couplings to join dissimilar DWV pipe and fittings above ground up to and including 15-in. pipe and fittings. This standard is intended to cover reducing couplings used to join pipes and fittings of different sizes, materials, and different outside diameters. 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 The committee with jurisdiction over this standard is not aware of any comparable standards published by other organizations. 1.4 The following precaution comment pertains only to the test method portion, Section 7 , of this specification. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 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.