Innovation Polymers in partnership with Materials Research Institute has developed a new and innovative phased array wedge design that improves phased array sectorial scanning of HDPE butt fusion joints. We have done this by incorporating a damping material with a low velocity refracting wedge made with Aqualink™ for pulse-echo testing.
The new design overcomes issues commonly associated with existing options in the marketplace, which include negative refraction when using hard plastics causing a weak signal. Large footprints limiting close approach when using water membranes. And easy adaptability to existing scanning systems.
Using a compact design and unique processing technique, we have been able to produce wedges that integrate with a number of widely used phased array probes.Download the product overview brochure
Applications exist where ultrasonic probes are required to be in place for long periods of time, sometimes in relatively extreme conditions. Typically, ultrasonic corrosion monitoring and ultrasonic flow metering place probes on a surface and take readings on a continuous or periodic basis. Water soluble gels eventually dry and the coupling effect is reduced and then lost.
Innovation Polymers has developed a new ultrasonic couplant that permits long term probe placement without significant coupling losses. The material is a high viscosity liquid polymer with virtually no evaporation at normal working temperatures. The tacky texture makes it an effective pressure sensitive adhesive i.e. it forms a bond when pressure is applied. One drop covering the wedge to probe contact surface can provide continuous coupling for several months.Download the product overview brochure
High Density Poly Ethylene (HDPE) pipe is becoming a popular substitute for steel pipe. Varieties of polyethylene used in industry can have an acoustic velocity range from about 2100m/s to about 2600m/s. Using PMMA or polystyrene as a refracting wedge material could result in very little refraction or even negative refraction. Elastomeric materials designed by Innovation Polymers range from approximately 1025m/s to about 1600m/s, ensuring positive refraction for all applications on polyethylene.
Innovation Polymers has designed wedges specifically for TOFD applications on HDPE. Interchangeable plugs made from Innovation Polymers’ low velocity elastomeric polymers permits the user to select a refracted-angle option best suited for the TOFD inspection at hand. These wedges are primarily intended for the TOFD inspection of high density polyethylene butt fusion joints. The modular concept consists of a standard housing, replaceable plug inserts and a threaded plate to accommodate different sized probes up to 12.5mm (0.5 inch) diameter.Download the product overview brochure
Phased Array or Conventional Wedge Designs
Using low velocity wedge material such as ACE™ provides a good velocity ratio resulting in less beam distortion. The higher refracted beams can be generated with lower incident angles. 35.4° incidence produces a 60° refracted angle in HDPE (Vel. 2330m/s) and a useful lateral wave can be obtained even with a 5MHz probe.