An ultrasonic testing portal for heavy-wall seamless tubes within a diameter range from 178 – 419 mm, a wall thickness range from 20 – 100 mm and a tube length from 4 – 15 m is presented in this article. During the inspection, the tube is scanned with helical testing traces. While the tube is rotating, the probes are linearly guided along its longitudinal axis and coupled onto the tube surface in the 12 o’clock position. Special about the testing system is the way to couple the ultrasound into the tube. Water jet coupling (also called squirter technique) is used, which means that the water path between probe and tube surface is in the order of several centimetres.
