Magnetic Analysis Corp. (MAC) has developed an Ultrasonic Spin-The-Tube inspection system utilizing MAC’s Automated Pitch Control (APC) Technology and Precision Design Conveyor. Capable of handling a larger range of diameters and material that is not as straight as usually required by other test systems, the APC design and conveyor provide a significant new option for this application.
At the center of MAC’s full body tube test system is the unique APC transducer carrier and the precision design ”Spin-The-Tube” conveyor. With the use of a simple dial-in pitch controller, the operator can set a precise angle of helical pitch for the conveyor’s rotation of the tube. The conveyor spins the tube longitudinally past the ultrasonic transducers at the correct pitch, and the APC follower rolls automatically adapt to this angle. This allows the APC carrier, with its simple immersion water tray, to handle ovate and unstraight tube and reliably maintain constant coupling and water path during the test. The result is a highly accurate, reliable ultrasonic inspection system. This design also ensures minimal wear and permits testing of materials with ovality and straightness problems.
A recent system was installed and commissioned at a major US Mid-West producer of Seamless and DOM Tubular Products. The machine was designed for Longitudinal, Transverse, Wall Thickness and Lamination Detection to the 5% and 10% level. This particular application required two Test Heads and 30 transducer elements, however, the specific layout and scan plan can be easily modified depending on the customer’s test specifications. The test heads are lifted into the test position beneath the tube by air cylinders before the first transducer is reached, and drops out of position after the tube end passes the last transducer. This ensures the head is securely positioned after the first follower roll approaches, preventing possible damage during normal operation. All mechanical components are manufactured from stainless steel to prevent corrosion and premature wear.
The system’s design allows the tube producer to test a broad range of tube diameters from 50mm to 355mm (2” – 14”) diameter, without changing bushings or glands. A simple one-knob adjustment control and convenient diameter scale are used for changes in dimension, ensuring the UT sound entry point and incident angles remain constant for any tube size.
Material Handling is a critical aspect of any Spin-The Tube inspection system and MAC has manufactured a premium grade conveyor to compliment the APC Test Heads. This conveyor is engineered from an NDT perspective and ensures efficient material handling and containment. The Powered Roller Heads are robustly designed and accurately maintain the inspection helix and rotational speed to assure there are no untested areas within the Scan Plan.
MAC’s APC Full Body Tester, with or without the conveyor, can be seamlessly installed into an existing production line, whether it’s a new system or an upgrade of an older unit. It operates with the familiar interface of the Echomac® FD electronics which provide the critical software for controlling the transducers and receiving, adjusting, analyzing and reporting test results.
