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PolyTest system demonstrations in Israel

PolyTest was demonstrated on:

  • 8 kilometres of OD 1000mm SDR17 butt fusion welds for the Hiraya Dan Recycling Authority
  • multiple dimension PEX pipes and electrofusion joints for a well at the Tel Aviv Hilton hotel
  • 2 kilometres of OD 900mm SDR21 butt fusion welds for the Nahal Yarmot Valley Sewage Collection project.

The demonstrations used the Polytest procedure for butt fusion and electrofusion joints with data collected and analysed for volumetric defects.  Phased array ultrasonic testing (PAUT), incorporating multi-element transducers fitted to a membrane sealed water-box wedge, was used.

The objective of the demonstrations was to illustrate to the clients the capabilities of Polytest in respect of HDPE pipe welds, demonstrating the scan data capture process in a site environment and the analysis functions to reveal potential flaws with subsequent reporting. It also highlighted the relevance of the inspection system to new installation projects as well as for existing infrastructure.

Figure 1 Butt fusion weld inspection on Nahal Yarmot Valley pipeline
Figure 1 Butt fusion weld inspection on Nahal Yarmot Valley pipeline

Polytest uses PAUT probes; these operate at optimal frequencies on polyethylene (PE) pipes with wall thicknesses of between 8 and 72mm.  Membrane water wedges give full coverage of the weld fusion zone and a flexible scanner accommodates pipes with diameters from 90 to 900mm.  The system is able to detect all types of flaw that can occur in PE pipe welds and is currently in active use in the water and gas distribution, and nuclear sectors.

All the PolyTest demonstrations were carried out successfully and none of the results showed critical defects, where any defects were shown at all.

The demonstrations illustrated that the PolyTest system is a versatile, site-deployable inspection tool for both butt fusion and electrofusion welds in HDPE piping across a wide range of diameters and positions.  It also confirmed that scaling up for diameters of over 900mm can be easily achieved by adding more chain links to the testing system, although longer term, validation work is required on detection and sizing for pipe wall thicknesses in excess of 72mm in larger diameter pipes.

For more information please email


Figure 2 Electrofusion weld inspection at Tel Aviv Hilton hotel
Figure 2 Electrofusion weld inspection at Tel Aviv Hilton hotel
Avatar Doug Wylie Team Manager - NDT Products

Following a 23-year career in the RAF, Doug joined TWI in January 2008 as NDT Programme Manager, Training and Examination Services, responsible for the delivery of the non-destructive testing (NDT) training across four venues in the UK. In October 2011, after completion of a BEng (Hons) degree through the Open University, he transferred to the NDT Section.

Doug, an Incorporated Engineer and multi-method NDT Level 2/3, has experience across a variety of industry sectors. He has been involved in NDT application both on- and offshore, third-party inspection witnessing, procedure development and review, collaborative projects and single-client project support. As a team manager he is now responsible for developing the delivery of NDT products in TWI’s Integrity Management Group, and is also leading the innovation project ‘PolyTest’, a new system for inspecting welded joints in HDPE piping.

Away from TWI he is past chair of the BINDT Membership, Qualification & Education Committee and a current Vice President of BINDT.