1.1 本试验方法涵盖了一种标准化方法，用于确定设计用于限制热塑性天然气服务管线中流量或停止流量的溢流阀（EFV）的性能。 2. 1.2 所有试验均应使用空气作为试验流体。除非另有说明，否则所有流速均以0.6相对密度天然气的标准立方英尺/小时表示。 1.3 该测试方法可识别两种类型的EFV。一种类型是溢流阀旁路（EFVB），在跳闸后允许少量气体通过（旁路），通常作为自动重置装置的一种方式。第二种类型是溢流阀非旁通阀（EFVNB），用于跳闸关闭，形成基本气密密封。 1.4 本试验方法涵盖的性能特征包括跳闸点的流量、EFV的压降、EFVB的旁通流量或跳闸后通过EFVNB的泄漏率，以及验证EFV可以重置。 1.4.1 气体分配系统可能包含冷凝液和微粒，如有机物、沙子、污垢和铁化合物。现场经验表明，一些EFV的运行特性可能会受到这些材料累积的影响。截面试验 11 旨在提供一种简单、廉价、可重复的测试，量化煤油均匀涂层和被指定量氧化铁粉末污染的煤油对EFV操作特性的影响（如有）。 1.5 本试验方法涵盖的溢流阀通常具有以下特性:额定压力高达125 psig（0.86 MPa）；跳闸流量介于200 英尺 3. /h和2500英尺 3. /h（5.66 m 3. /h和70.8米 3. /h） 在10 psig（0.07 MPa）下；最低温度额定值为0°F（-18°C），最高温度额定值为100 华氏度（38 °C）。 1.6 本试验方法涵盖的EFV的构造应适合不小于 1. / 2. 电流互感器且不大于1 1. / 4. IPS，包括管道和油管尺寸。 1.7 测试将在67 °F±10 华氏度（19.4 °C±5.5 °C）。可选试验温度为100 华氏度 ± 10 华氏度（37.7 °C±5.5 °C）和0±10°F（-18±5.5°C）。所有流速必须校正至标准条件。 1.8 本试验方法适用于安装在热塑性管道系统中的EFV。然而，预计该试验方法也可用于其他管道系统中的类似装置。 1.9 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。 1.10 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。 有关具体预防措施，请参阅第节 8. . 1.11 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 本试验方法旨在用于评估用于住宅和小型商用热塑性天然气服务管线的EFV。测试的可能应用包括制造商的产品设计和质量控制测试以及天然气公用事业公司的产品验收测试。 5.2 本试验方法的使用者应注意，试验装置中测得的流量和压力可能与现场安装中测得的流量和压力不太相关。因此，用户应进行充分的测试，以确保任何特定EFV将在实际使用的现场安装中实现其预期功能。

1.1 This test method covers a standardized method to determine the performance of excess flow valves (EFVs) designed to limit flow or stop flow in thermoplastic natural gas service lines. 2 1.2 All tests are intended to be performed using air as the test fluid. Unless otherwise stated, all flow rates are reported in standard cubic feet per hour of 0.6 relative density natural gas. 1.3 The test method recognizes two types of EFV. One type, an excess flow valve-bypass (EFVB), allows a small amount of gas to bleed through (bypass) after it has tripped, usually as a means of automatically resetting the device. The second type, an excess flow valve-non bypass (EFVNB), is intended to trip shut forming an essentially gas tight seal. 1.4 The performance characteristics covered in this test method include flow at trip point, pressure drop across the EFV, bypass flow rate of the EFVB or leak rate through the EFVNB after trip, and verification that the EFV can be reset. 1.4.1 Gas distribution systems may contain condensates and particulates such as organic matter, sand, dirt, and iron compounds. Field experience has shown that the operating characteristics of some EFVs may be affected by accumulations of these materials. The tests of Section 11 were developed to provide a simple, inexpensive, reproducible test that quantifies the effect, if any, of a uniform coating of kerosene and of kerosene contaminated with a specified amount of ferric oxide powder on an EFV's operating characteristics. 1.5 Excess flow valves covered by this test method will normally have the following characteristics: a pressure rating of up to 125 psig (0.86 MPa); a trip flow of between 200 ft 3 /h and 2500 ft 3 /h (5.66 m 3 /h and 70.8 m 3 /h) at 10 psig (0.07 MPa); a minimum temperature rating of 0°F(–18°C), and a maximum temperature rating of 100 °F (38 °C). 1.6 The EFVs covered by this test method shall be constructed to fit piping systems no smaller than 1 / 2 CTS and no larger than 1 1 / 4 IPS, including both pipe and tubing sizes. 1.7 Tests will be performed at 67 °F ± 10 °F (19.4 °C ± 5.5 °C). Alternative optional test temperatures are 100 °F ± 10 °F (37.7 °C ± 5.5 °C) and 0 ± 10°F (–18 ± 5.5°C). All flow rates must be corrected to standard conditions. 1.8 This test method was written for EFVs installed in thermoplastic piping systems. However, it is expected that the test method may also be used for similar devices in other piping systems. 1.9 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. 1.10 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. For specific precautions, see Section 8 . 1.11 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 This test method is intended to be used for the evaluation of EFVs manufactured for use on residential and small commercial thermoplastic natural gas service lines. Possible applications of the test include product design and quality control testing by a manufacturer and product acceptance testing by a natural gas utility. 5.2 The user of this test method should be aware that the flows and pressures measured in the test apparatus may not correlate well with those measured in a field installation. Therefore, the user should conduct sufficient tests to ensure that any specific EFV will carry out its intended function in the actual field installation used.