1.1 本规程规定了聚乙烯管道系统中电熔接头的超声波检测（UT）程序。本实施例提供了一种用于超声脉冲回波直波束接触测试的超声检查程序，使用通过搜索单元与被检查材料的直接接触引入的直波束纵波。 1.2 本规程适用于聚乙烯电熔承口（例如联轴器）和鞍形（例如三通）配件，用于标称直径为0.5的聚乙烯管道 英寸至12 英寸[12 mm至300mm]，管道尺寸比（DR）在6.3至17的范围内。如果该技术能够证明在相同壁厚和几何形状的实体模型上提供足够的检测，则可以使用该实践来测试更大和更小的厚度以及更大和较小的直径。 1.3 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 . 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管道应用的HDPE和MDPE材料 D3350 . 1.4 本规程未规定验收标准。参考规范 F1055 和实践 F1290 破坏性验收标准。 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 本规程主要用于聚乙烯管道系统施工和维护中使用的电熔接头的手动超声波扫描。 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 此做法并非旨在提供100 % 联合检查。本规程规定了仅代表焊接界面一部分的最小扫描网格。因此，存在忽略缺陷的可能性。此外，焊接界面的选定区域可能无法接近。检查范围应在合同协议中规定。 5.4 连接过程可能会出现各种缺陷，包括但不限于未熔合、颗粒污染、刺入深度短、夹杂物和空隙。 5.5 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。这使得参考块必须由具有相同规格的管道制成 D3350 密度细胞分类作为所检查的电融合拟合。 （A） 文献中已经注意到速度和衰减值的范围 ( 1- 9 ) . 5.6 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/英寸]，2 MHz），不能使用剪切模式进行实际检查 ( 6. ) . 5.7 由于应用范围广泛，聚乙烯管的接头验收标准通常是特定于项目的。 5.8 聚乙烯管与联轴器之间以及管与鞍座之间典型电熔接头的横截面图如所示 图1 和 图2 分别地 图1 电熔耦合接头的典型横截面图 图2 电熔鞍形三通接头的典型横截面图

1.1 This practice establishes a procedure for ultrasonic testing (UT) of electrofusion joints in polyethylene pipe systems. This practice provides one ultrasonic examination procedure for ultrasonic pulse-echo straight beam contact testing, using straight-beam longitudinal waves introduced by direct contact of the search unit with the material being examined. 1.2 The practice is intended to be used on polyethylene electrofusion socket (for example, couplings) and saddle (for example, tees) fittings for use on polyethylene pipe ranging in diameters from nominal 0.5 in. to 12 in. [12 mm to 300 mm] with pipe dimension ratios (DR) ranging from 6.3 to 17. Greater and lesser thicknesses and greater and lesser diameters may be tested using this practice if the technique can be demonstrated to provide adequate detection on mockups of the same wall thickness and geometry. 1.3 This practice does not address ultrasonic examination of butt fusions. Ultrasonic testing of polyethylene butt fusion joints is addressed in Practice E3044/E3044M . 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 materials for pipe applications defined by Specification D3350 . 1.4 This practice does not specify acceptance criteria. Refer to Specification F1055 and Practice F1290 for destructive 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 primarily for the manual ultrasonic scanning 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 This practice is not intended to provide 100 % joint examination. This practice specifies a minimum scanning grid that represents only a portion of the welded interface. As such, there exists a possibility of omitting flaws. In addition, selected areas of the welded interface may not be accessible. The extent of examination shall be specified in the contractual agreement. 5.4 The joining process can be subject to a variety of flaws including, but not limited to, lack of fusion, particulate contamination, short-stab depth, inclusions, and voids. 5.5 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 pipes with the same Specification D3350 density cell classification as the electrofusion fitting examined. (A) A range of velocity and attenuation values have been noted in the literature ( 1- 9 ) . 5.6 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/inch] at 2 MHz) no practical examinations can be carried out using shear mode ( 6 ) . 5.7 Due to the wide range of applications, joint acceptance criteria for polyethylene pipe are usually project-specific. 5.8 A cross-sectional view of typical electrofusion joints between polyethylene pipe and coupling and between pipe and saddle are illustrated in Fig. 1 and Fig. 2 , respectively. FIG. 1 Typical Cross-Sectional View of an Electrofusion Coupling Joint FIG. 2 Typical Cross-Sectional View of an Electrofusion Saddle Tee Joint