Ultrasonic tester inspects tube weld zones online during continuous production

Designed to test for longitudinally oriented defects typical of the ERW process, Magnetic Analysis Corp.’s Echomac® WLD ultrasonic testing system has new operating conveniences for inspecting tube weld zones online during continuous production.

The system typically comprises four channels using both CW and CCW sounds modes for detecting ID and OD longitudinal defects between 5 and 10 percent of wall thickness. Additional channels can be added, depending on the application.

The system includes Echomac® instrumentation and a test head incorporating transducer assemblies with irrigated shoes for constant coupling with the tube being tested. Maintaining optimal positioning of the transducer assemblies with respect to the weld zone is accomplished with a new joystick that allows the operator to rotate the entire test head by means of a high-resolution stepper motor. At any time the operator can verify that the transducers are correctly positioned by observing a monitor showing a laser beam that must bisect the weld center. With this control, the transducer assemblies can be rotated to follow the weld to achieve continuous testing over a weld position of 10 to 2 o’clock. Individual adjustment of each transducer to achieve optimal position for CW and CCW direction is available. A coupling alarm alerts the operator to any coupling loss between any transducer and the tube caused by water loss or improper alignment.

The individual irrigated transducer shoes can exchanged to accommodate tube size changes in 5 seconds using the system’s quick disconnect mechanisms.

The test head is supported by a strong gantry that allows for operating on the weld line for mill testing, or offline for easy calibration for a new tube size. A precision roller assembly is located in the offline position to allow for calibration of the transducers. Once the calibration is achieved, the test head is moved back to the online position for production line testing.

An oversize stainless steel catch pan is used to help control splash water and keep the operator area relatively dry.

The Allen Bradley system controls are designed for simple operation, but have flexible features accessible in the flat panel control display, the company states. Siemens Controls are also available. The remote operator station contains essential controls, including the video monitor. The instrument system is programmed with the transducer locations, and a spray marker located downstream is automatically instructed to spray paint onto the actual defect location to enable sorting the cut tubes.

Separate colors can be selected for OD and ID condition. Chart recordings also are generated that represent the tube condition of each cut tube. These are stored in digital format and archived for future retrieval.