scope:

This document describes the phased array ultrasonic testing (PAUT) of polyethylene butt fusion (BF) joints, including pipe-to-pipe, pipe-to-fitting and fitting-to-fitting joints, used for the conveyance of fluids. This document provides a test whereby the presence of imperfections such as voids, inclusions, lack of fusions, misalignment and particulate contamination in the BF joints can be detected. The document is only applicable to polyethylene pipes and fittings without a barrier to ultrasonic waves.

This document also provides requirements for procedure qualification and guidance for personnel qualifications, which are essential for the application of this test method.

This document also covers the equipment, preparation and performance of the test, as well as the indication assessment and the reporting for polyethylene BF joints. The acceptance criteria are not covered in this document.

NOTE 1 At the present time, laboratory experiences exist on the use of PAUT for polyethylene BF joints and/or reference blocks of wall thickness between 8 mm to 100 mm.^{[7][8][9][10][11]} Field experience on BF joints in PE80 and PE100 materials has been reported.^[12]

NOTE 2 Interlaboratory testing has shown that PAUT is a viable method for enhancing the integrity assessment of butt-fusion joints.^[13][16]

NOTE 3 PAUT techniques for cold fusion detection are known to be available. However, further research, verification and experience are needed to transfer the technique into an ISO International Standard. This document does not provide any information regarding the detection of cold fusions.^[16]