【国外标准】 Standard Practice for Microwave Examination of Polyethylene Electrofusion Joints Used in Piping Application

5.1 Polyethylene piping has been used instead of steel alloys in the petrochemical, power, water, gas distribution, and mining industries due to its resistance to corrosion and erosion and reliability. Recently, polyethylene pipe has also been used for nuclear safety related cooling water applications.5.2 MW examination is useful for detecting various flaws that are known to occur in polyethylene electrofused joints.1.1 This practice covers microwave (MW) examination of electrofusion joints made entirely of polyethylene for the purpose of joining polyethylene piping.NOTE 1: The notes in this practice are for information only and shall not be considered part of this practice.NOTE 2: This practice references HDPE and MDPE for pipe applications as defined by Specification D3350.1.2 The electrofusion joining process can be subject to a variety of flaws including, but not limited to, lack of fusion, particulate contamination, inclusions, and voids.1.3 The practice is intended to be used on joint thicknesses of 0.5 in. to 4 in. (12 mm to 100 mm) and diameters 4 in. (100 mm) and greater. Greater and lesser thicknesses and lesser diameters may be tested using this standard practice if the technique can be demonstrated to provide adequate detection on mockups of the same wall thickness and geometry.1.4 This practice can be applied to post assembly inspection of polyethylene electrofusion joints.1.5 This practice does not specify acceptance criteria.1.6 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.1.7 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.1.8 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.