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Introduction of the Multiple Angle TOFD Wedge

This new wedge has been created for ultrasonic testing of High Density Poly Ethylene (HDPE) pipe

High Density Poly Ethylene (HDPE) pipe is now a popular substitute for steel pipe. Varieties of HDPE used in industry have an acoustic velocity range from ≈ 2100 m/s to ≈ 2600 m/s. Using PMMA or polystyrene as a refracting wedge material could result in very little to negative refraction. Elastomeric materials designed by Innovation Polymers range from ≈ 1025 m/s to ≈ 1600 m/s, ensuring positive refraction for all applications on polyethylene.

Innovation Polymers has designed wedges specifically for TOFD applications on HDPE. Interchangeable plugs made from  Aqualene™, ACE™ and Aqualink™ permit the user to select a refracted angle option best suited for the TOFD inspection at hand. These wedges are primarily intended for TOFD inspection of HDPE butt fusion joints. The modular concept of a standard housing, replaceable plug inserts and a threaded plate to accommodate different sized probes up to 12.5 mm (0.5 inches) diameter.

Multiple Angle TOFD wedges for HDPE inspections
  • Standard plugs are available in Aqualene™, ACE™ and Aqualink™.
  • Standard plates are anodized aluminum with 3/8-32 or 11/16-24 threaded opening for probes.
  • Standard incident angle is 35° on a flat contact surface.
Refraction Angles based on Aqualene™, ACE™ and Aqualink™
Polymer Aqualene™ 300

Refracted Angle (°)
ACE™ 400

Refracted Angle (°)
Aqualink™ 100

Refracted Angle (°)
Velocity (m/s)
1590 m/s
1540 m/s
1480 m/s
2000
46
48
51
2100
49
51
54
2200
53
55
58
2300
56
59
63
2400
60
63
68
2500
65
69
76
2600
70
76
Internal Refraction

Plug options on HDPE with acoustic velocity 2400 m/s

The flat wedge design with the soft polymer plugs allows the wedge to form to radii as low as 3″ OD. Radiused wedges are available as a special order.

The standard materials provide refracted angles based on the polymer tested. Use determines the best plug material based on the polymer tested, its thickness, and the Probe Centre Spacing (PCS) for the desired depth of the beam crossing point. 

Wave analysis of Innovation Polymers materials
Scan of 25.5 mm HDPE (2530 m/s) with ACE™ 400 insert. PCS = 82 mm.
Five 10 mm long Vee notches.
  • Supplied with irrigation nozzles
  • Custom modifications are available
  • Different incident angles available
  • Threaded probe-plates and curvatures can be added

About Innovation Polymers:

Innovation Polymers is a leader in acoustic capable polymer solutions for the non-destructive testing industry, providing high-quality products and services to clients across a range of industries. With a commitment to innovation and customer satisfaction, the company has the capability to develop a wide range of unique sound coupling polymeric media and has earned a reputation as a trusted partner in the industry.