1.1 本规程涵盖了在暴露于热后评估模制聚氯乙烯塑料管件质量的程序。 1.2 单位- 以英寸-磅或国际单位制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。 注1: 方括号内的数值为国际单位要求。 1.3 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。 1.4 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。 ====意义和用途====== 3.1 本规程适用于区分正确模压和不正确模压的PVC塑料管件。它可以用于: 3.1.1 确定是否存在冷段塞或未熔合区域( 注释2 ), 3.1.2 确定成型过程产生的压入应力量( 附注3 ), 3.1.3 显示污染，以及 3.1.4 显示焊缝的质量。 注2: 冷段塞是一种材料，其进入模具的温度明显低于其余部分。 注3: 无应力零件通常比高应力零件具有更好的性能和更高的强度。无应力零件在接触化学品时通常反应更好。

1.1 This practice covers a procedure for evaluating the quality of molded poly(vinyl chloride) (PVC) plastic pipe fittings after exposure to heat. 1.2 Units— The values stated in either inch-pound or SI 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 non-conformance with the standard. Note 1: The values in square brackets are SI units requirements. 1.3 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. 1.4 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. ====== Significance And Use ====== 3.1 This practice is applicable to distinguish between properly and improperly molded PVC plastic pipe fittings. It can be used to: 3.1.1 Determine whether cold slugs or unfused areas are present ( Note 2 ), 3.1.2 Determine the amount of molded-in stress produced by the molding process ( Note 3 ), 3.1.3 Reveal contamination, and 3.1.4 Show the quality of the weld line. Note 2: A cold slug is a piece of material that enters the mold at a significantly lower temperature than the rest of the mass. Note 3: A stress-free part will generally have better properties and higher strength than those with a high degree of stress. Stress-free parts will generally react better when exposed to chemicals.