PolyTest™ System : NDE of welded joints in polyethylene pipe
The PolyTest™ System is an ultrasonic inspection equipment designed and optimised specifically for the volumetric non-destructive testing of electrofusion (EF) and butt fusion (BF) joints in polyethylene (PE) pipes. This system has originally emerdged from the Polytest project, in which M2M has been working to develop the phased-array unit (GEKKO) with its software (Capture) for flaw detection and sizing.
In order to carry a non-destructive evaluation of welded joints in polyethylene pipes, the PolyTest™ system includes:
- - phased array ultrasonic probes, operating at the optimal frequencies for PE pipes of wall thicknesses between 8 and at least 72mm
- - membrane water wedges, designed to give full coverage of the weld fusion zone
- - a simple flexible scanner accommodating pipes with diameters from 90 to 900mm.
The PolyTest™ system is supported with procedures to enable detection of all types of flaw that can occur in PE pipe welds, including planar flaws, particulate contamination and cold welds. Extensive performance testing has been carried out to determine the acceptance criteria that should be applied, and the system’s inspection capabilities have been shown to be effective on joints containing known flaws in pipe diameters up to 900mm.
The system has been in use in the water and gas distribution, and nuclear sectors for over 3 years, with interest from other sectors such as mining, but is suitable for any industry that has a need for the high integrity inspection of PE welds.
With a lack of a commercially device to verify through-weld integrity, it was needed to develop a system for the inspection of welds in PE/plastic piping.
Main Project Tasks:
Under this Polytest project, M2M has developed a custom software package for the phased-array flaw detector GEKKO, to inspect any given butt fusion (BF) or electrofusion (EF) weld joint in HDPE piping.
GEKKO is a very innovative portable equipment, developed and commercialized by M2M since 2014. This flaw detector is the first and only one in the world able to handle standard phased-array applications and Total Focusing Method in real time. Dedicated application software would be developed in the frame of this project allowing combining advanced techniques such as TFM with automated diagnostics. These applications tools dedicated to plastic examination will be embedded in GEKKO instrument. At the end, an easy and dedicated interface integrating automated diagnostics will allow a low level operator to take better decisions on the reliability of components.