1.1 本规程涵盖聚乙烯管道系统中电熔接头的相控阵超声检测（PAUT）程序。尽管高密度聚乙烯（HDPE）和中密度聚乙烯（MDPE）材料是最常用的，但所述程序也可应用于其他类型的聚乙烯。 注1: 本规程中的注释仅供参考，不应视为本规程的一部分。 注2: 本标准参考了规范规定的HDPE和MDPE管道应用 D3350 . 1.2 本规程不涉及对接融合的超声波检查。实践中介绍了聚乙烯熔接对接接头的超声波检测 E3044/E3044M . 1.3 聚乙烯电熔接头的相控阵超声检测（PAUT）使用安装在零度楔上的阵列探头引入的纵波。本规程适用于标称直径为4的聚乙烯管上使用的聚乙烯电熔接头 英寸至28 英寸（100 mm至710 mm），并且用于从0。 3. 英寸至2 英寸（8 mm至50 mm）。如果该技术能够证明在相同几何形状的实体模型上提供足够的检测，则可以使用该标准实践来测试更大和更小的厚度和直径。 1.4 本规程未规定验收标准。 1.5 以国际单位制或英寸磅单位表示的数值应单独视为标准。每个系统中规定的值不一定是完全相等的；因此，为了确保符合标准，每个系统应独立使用，并且不得将两个系统的值组合使用。 1.6 本标准并不旨在解决与其使用相关的所有安全问题（如有）。本标准的使用者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。 1.7 本国际标准是根据世界贸易组织技术性贸易壁垒委员会发布的《关于制定国际标准、指南和建议的原则的决定》中确立的国际公认的标准化原则制定的。 ====意义和用途====== 5.1 本规程适用于聚乙烯管道系统施工和维护中使用的电熔接头的半自动或自动超声波检查。 5.2 聚乙烯管道由于其可靠性以及耐腐蚀和侵蚀性，已被用于石化、电力、水、天然气分配和采矿行业，而不是钢合金。 5.3 连接过程可能会出现各种缺陷，包括但不限于: 未熔合、冷熔合、颗粒污染、夹杂物、短刺深度和空隙。 5.4 聚乙烯材料可能具有一系列声学特性，这使得电熔联合检查变得困难。聚乙烯材料具有高度的衰减性，这通常限制了更高超声频率的使用。它还表现出自然的高频滤波效果。中提供了声学特性范围的示例 表1 . 6. 该表指出了文献中报道的广泛的声速范围。 这使得参考试块必须由管道级聚乙烯制成，其密度等级与所检查的电熔配件相同。 （A） 文献中已经注意到速度和衰减值的范围 ( 1- 9 ) . 5.5 据报道，聚乙烯的剪切速度为987 m/s。然而，由于剪切模式下的极高衰减（约为5 dB/mm（127 dB/in.）在2 MHz），不能使用剪切模式进行实际检查 ( 6. ) . 5.6 由于应用范围广泛，聚乙烯管的联合验收标准通常是项目- 具体的 5.7 聚乙烯管和电熔耦合器之间的典型接头的横截面图如所示 图1 . 图1 电熔耦合接头的典型横截面图

1.1 This practice covers procedures for phased array ultrasonic testing (PAUT) of electrofusion joints in polyethylene pipe systems. Although high density polyethylene (HDPE) and medium density polyethylene (MDPE) materials are most commonly used, the procedures described may apply to other types of polyethylene. Note 1: The notes in this practice are for information only and shall not be considered part of this practice. Note 2: This standard references HDPE and MDPE for pipe applications defined by Specification D3350 . 1.2 This practice does not address ultrasonic examination of butt fusions. Ultrasonic testing of polyethylene butt fusion joints is addressed in Practice E3044/E3044M . 1.3 Phased array ultrasonic testing (PAUT) of polyethylene electrofusion joints uses longitudinal waves introduced by an array probe mounted on a zero degree wedge. This practice is intended to be used on polyethylene electrofusion couplings for use on polyethylene pipe ranging in diameters from nominal 4 in. to 28 in. (100 mm to 710 mm) and for coupling wall thicknesses from 0.3 in. to 2 in. (8 mm to 50 mm). Greater and lesser thicknesses and diameters may be tested using this standard practice if the technique can be demonstrated to provide adequate detection on mockups of the same geometry. 1.4 This practice does not specify acceptance criteria. 1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined. 1.6 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. 1.7 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 practice is intended for the semi-automated or automated ultrasonic examination of electrofusion joints used in the construction and maintenance of polyethylene piping systems. 5.2 Polyethylene piping has been used instead of steel alloys in the petrochemical, power, water, gas distribution, and mining industries due to its reliability and resistance to corrosion and erosion. 5.3 The joining process can be subject to a variety of flaws including, but not limited to: lack of fusion, cold fusion, particulate contamination, inclusions, short stab depth, and voids. 5.4 Polyethylene material can have a range of acoustic characteristics that make electrofusion joint examination difficult. Polyethylene materials are highly attenuative, which often limits the use of higher ultrasonic frequencies. It also exhibits a natural high frequency filtering effect. An example of the range of acoustic characteristics is provided in Table 1 . 6 The table notes the wide range of acoustic velocities reported in the literature. This makes it essential that the reference blocks are made from pipe grade polyethylene with the same density cell class as the electrofusion fitting examined. (A) A range of velocity and attenuation values have been noted in the literature ( 1- 9 ) . 5.5 Polyethylene is reported to have a shear velocity of 987 m/s. However, due to extremely high attenuation in shear mode (on the order of 5 dB/mm (127 dB/in.) at 2 MHz) no practical examinations can be carried out using shear mode ( 6 ) . 5.6 Due to the wide range of applications, joint acceptance criteria for polyethylene pipe are usually project-specific. 5.7 A cross-sectional view of a typical joint between polyethylene pipe and an electrofusion coupling is illustrated in Fig. 1 . FIG. 1 Typical Cross-Sectional View of an Electrofusion Coupling Joint