1.1 本试验方法描述了评估根据PEX规范（如规范）生产的交联聚乙烯（PEX）管道的长期氯化水抗氧化性的一般要求 F876 或规格 F2788/F2788M 暴露在热的氯化水中。本试验方法概述了加压通流试验系统的要求、典型试验压力、试验流体特性、故障类型和数据分析。 注1: 其他已知的消毒系统（二氧化氯、臭氧和氯胺）也用于保护饮用水。游离氯是当今最常用的消毒剂。PPI的一个研究项目检查了游离氯和氯胺在PEX管道上的相对侵蚀性，两者在同一时间点。 0 ppm浓度和相同的试验温度。测试结果表明，在测试条件下，使用氯胺测试的管道故障时间比使用游离氯测试的管道故障时间长约40%。基于这些结果，数据表明氯胺对PEX管道的侵蚀性低于游离氯。 1.2 通过对三种最常见的商业交联方法（硅烷、过氧化氢和电子束）生产的PEX管进行事先测试，确定了测试温度、测试环向应力和其他测试标准的指南和要求（见 注释2 ). 通常出现在PEX热水和冷水分配系统中的其他相关系统组件可以使用PEX管道或管道进行评估。 当将PEX管道或管子和配件作为一个系统进行测试时，建议将预期的最终用途配件类型和材料包括在测试电路中，因为已知某些配件类型和材料会影响故障时间。使用的样本应代表正在调查的管道产品和材料。 注2: 本试验方法中描述的程序（对试验温度或应力或两者进行了一些修改）已用于评估由聚丁烯（PB）、聚乙烯（PE）、聚丙烯（PP）、多层（聚合物金属复合材料）、铜和不锈钢制成的管道。 1.3 本试验方法适用于用于运输含游离碳的饮用水的PEX管道或管道和系统- 消毒用氯。本试验方法中规定的试验流体的氧化电位超过了美国饮用水系统中的典型氧化电位。 1.4 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。 1.5 以下预防性警告仅适用于试验方法部分第节 12 ，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。 1.6 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====== 5.1 根据本试验方法得出的环境或氧化失效时间数据，根据第节进行分析 13 ，适用于外推到典型的最终使用温度和环向应力。外推值提供了测试PEX管道或管道或系统在与获得测试数据的条件等效的条件下对热氯化水氧化效应的阻力的相对指示。 材料或管道产品在实际安装和使用条件下的性能取决于许多因素，包括安装方法、使用模式、水质、局部应力的性质和大小，以及本试验方法中未涉及的实际运行冷热水分配系统的其他变量。因此，外推值不构成具有给定外推失效时间值的PEX管或系统在实际使用条件下在该时间段内的表现。

1.1 This test method describes the general requirements for evaluating the long-term, chlorinated water, oxidative resistance of cross-linked polyethylene (PEX) pipe or tubing produced in accordance with PEX specifications, such as Specification F876 or Specification F2788/F2788M by exposure to hot, chlorinated water. This test method outlines the requirements of a pressurized flow-through test system, typical test pressures, test-fluid characteristics, failure type, and data analysis. Note 1: Other known disinfecting systems (chlorine dioxide, ozone, and chloramines) are also used for protection of potable water. Free-chlorine is the most common disinfectant in use today. A PPI research project examined the relative aggressiveness of free chlorine and chloramines on PEX pipes, both at the same 4.0 ppm concentration and the same test temperatures. The results of the testing showed pipe failure times approximately 40% longer when tested with chloramines compared to testing with free chlorine, at the tested conditions. Based on these results, the data suggests that chloramines are less aggressive than free chlorine to PEX pipes. 1.2 Guidelines and requirements for test temperatures, test hoop stresses, and other test criteria have been established by prior testing of PEX pipe or tubing produced by the three most common commercial methods of cross-linking: silane, peroxide, and electron-beam (see Note 2 ). Other related system components that typically appear in a PEX hot-and-cold water distribution system can be evaluated with the PEX pipe or tubing. When testing PEX pipe or tubing and fittings as a system, it is recommended that the anticipated end-use fitting type(s) and material(s) be included in the test circuit since it is known that some fitting types and materials can impact failure times. Specimens used shall be representative of the piping product(s) and material(s) under investigation. Note 2: The procedures described in this test method (with some modifications of test temperatures or stresses, or both) have been used to evaluate pipes manufactured from polybutylene (PB), polyethylene (PE), polypropylene (PP), multilayer (polymer-metal composite), copper, and stainless steel. 1.3 This test method is applicable to PEX pipe or tubing and systems used for transport of potable water containing free-chlorine for disinfecting purposes. The oxidizing potential of the test-fluid specified in this test method exceeds that typically found in potable water systems across the United States. 1.4 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. 1.5 The following precautionary caveat pertains only to the test method portion, Section 12 , 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. 1.6 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 ====== 5.1 Environment or oxidative time-to-fail data derived from this test method, analyzed in accordance with Section 13 , are suitable for extrapolation to typical end-use temperatures and hoop stresses. The extrapolated value(s) provides a relative indication of the resistance of the tested PEX pipe or tubing or system to the oxidative effects of hot, chlorinated water for conditions equivalent to those conditions under which the test data were obtained. The performance of a material or piping product under actual conditions of installation and use is dependent upon a number of factors including installation methods, use patterns, water quality, nature and magnitude of localized stresses, and other variables of an actual, operating hot-and-cold water distribution system that are not addressed in this test method. As such, the extrapolated values do not constitute a representation that a PEX tube or system with a given extrapolated time-to-failure value will perform for that period of time under actual use conditions.