1.1 本规程涵盖了通过观察管道试样在180℃下暴露于烘箱中的热空气后的反应来评估挤出聚氯乙烯塑料管质量的程序 °C±5 °C（356 华氏度  ± 9 °F）至少持续30分钟。 1.2 以国际单位制表示的数值应视为标准值。国际单位制后括号中给出的值仅供参考，不被视为标准值。 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====== 2.1 本规程适用于区分正确挤压和不正确挤压的PVC塑料管。它可以用于: 2.1.1 在挤压之前或挤压过程中发现化合物不完全干燥( 注1 ), 2.1.2 确定挤压过程产生的管壁中是否存在应力( 注释2 ), 2.1.3 确定是否存在未使用的区域，以及 2.1.4 显示污染。 注1: 化合物中的残余水分在挤出温度下蒸发，通常在形成蒸汽时排出。管壁中积聚的水气袋是由于化合物不完全干燥所致，可能会降低管道的物理性能。 注2: 管道中的微小残余应力不会影响现场性能和可操作性。高残余应力对性能没有影响，但可能会影响安装过程中的可操作性。

1.1 This practice covers a procedure for estimating the quality of extruded poly (vinyl chloride) (PVC) plastic pipes by observing the reaction of pipe specimens after exposure to hot air in the oven at 180 °C ± 5 °C (356 °F  ± 9 °F) for 30 minutes minimum time duration. 1.2 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard. 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 ====== 2.1 This practice is applicable to distinguish between properly and improperly extruded PVC plastic pipe. It can be used to: 2.1.1 Reveal incomplete exsiccation of compound before or during extrusion ( Note 1 ), 2.1.2 Determine the presence of stress in the pipe wall produced by the extrusion process ( Note 2 ), 2.1.3 Determine whether unfused areas are present, and 2.1.4 Reveal contamination. Note 1: Residual moisture in the compound vaporizes at extrusion temperatures and is normally evacuated as it forms vapor. Pockets of moisture trapped in the pipe wall result from incomplete exsiccation of the compound, and may reduce the physical properties of the pipe. Note 2: Minor residual stress in the pipe will not impair field performance and handleability. High-residual stress has no proven effect on performance, but may impair handleability during installation.