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, the preparation and performance of the test, the indication assessment and the reporting for polyethylene BF joints. The assessment of ultrasonic indications and 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^{[1] to [5]}. Recently, field experience on BF joints in PE80 and PE100 materials has been reported^[6].

NOTE 2 Round robin testing has shown that PAUT is a viable method for enhancing the integrity assessment of BF joints^[7].

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 Standard. This document does not provide any information regarding the detection of cold fusions.

^[1] Hagglund F, Spicer M and Troughton M. Phased array ultrasonic testing of welded joints in plastics (PE) pipes, 6th Middle East NDT Conference and Exhibition, Bahrain, 7-10 October 2012

^[2] Hyungtaik Lim and Taegyung Kim Investigation of ultrasonic NDT techniques for class III HDPE piping butt-fusion joint, KSNT Conference, Changwon, Korea, 28-30 October 2015

^[3] Hyungtaik Lim and Taegyung Kim Recent Trends of NDE Technique & Associated R&D in HDPE Pipe Joints, KPVP Conference, Busan, Korea, 4-5 December 2014

^[4] PNNL Technical Letter Report 2008 Preliminary Assessment of NDE Methods on Inspection of HDPE Butt Fusion Piping Joints for Lack of Fusion

^[5] Caleb Frederick, Allen Porter and David Zimmerman. Ultrasonic Phased Array Test of Butt-Fusion Joints in High-Density Polyethylene, NC Paper No. ICONE17-75859, pp. 207-211, Brussels, Belgium, July 12-16, 2009

^[6] Troughton M, Hagglund F. On-site volumetric inspection of butt fusion and electrofusion joints in polyethylene pipes, Joining Plastics, 10, No.1, 2016

^[7] Advanced Nuclear Technology , Round Robin Study on Nondestructive Examination of HDPE Pipe Joints, 2017 EPRI Technical Report, 3002011397