TPT May 2017

T E CHNOLOG Y

Ultrasonic rotary test system UNICORN Automation (NDT) has supplied ultrasonic test systems globally for more than 20 years. It specialises in the ability to test hot finish tubes such as OCTG tubes using its unique contact shoe technique. The test systems can cope with off- centre tubes and the unique contact shoe raise/lower system allows the free passage of upset ends or threaded tube ends. With a maximum rotation speed of 700RPM test speeds of up to 40m/min are achievable.

by further increasing the radial guide clearances. A further problem can be that scale from the hot-finished product can build up in the water chamber and affect ultrasonic transmission. The extended range URP200/S resolves these issues by making the Unicorn contact shoe technology available for testing tubes in the (extended) 25 to 48mm diameter range. The alternative technique of rotating or spiraling a tube using a travelling or fixed carriage containing the transducers, although better than the water chamber from a signal repeatability point of view, has the drawback of being a relatively slow method of testing unless numerous transducers are employed; speed of tube rotation is also limited further when testing bent tubes. Unicorn Automation (NDT) – UK Email: cforryan@unicorn-automation.co.uk Website: www.unicorn-automation.co.uk

Tubes with pronounced hooked ends and poor straightness can be fully tested using this technique without any compromise to the test. Testing with contact shoes offers repeatability at the fast production speeds required by modern tube mills or third-party inspectors. To satisfy a growing requirement to test ever smaller diameters – tubing in the OCTG field, Unicorn have developed their contact shoe technique to test tubes down to the 25mm od size. The rotary head designated URP200/S now has the capability to test tubes with a diameter range 25mm to 220mm. The test head can be equipped with up to 30 transducers carrying out inspection for longitudinal, transverse, oblique and lamination/wall thickness defects.

Prior to extending the range of the URP200/S Unicorn could only offer the testing of tubes in the 25 to 48mm diameter range by means of a water chamber head. While these heads work well on tubes with a good surface finish and relatively small diameter variations, they have significant drawbacks when testing hot finished seamless tube with poor straightness, ovality, surface scale and upset ends. The main problem with water chamber heads when testing hot- finished seamless tubes is the need for relatively large radial guide clearances, which allow the tube to wander off- centre, leading to large signal variations and inconsistent test results. It is impractical to accommodate upset ends

Spain: Tel: +34 665 782908

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MAY 2017