Inspection of Pipeline Welds
An example of the Phased Array Automated Ultrasonic Testing (PA-AUT) of pipeline welds would be the inspection of double joints.
Double joints are produced in a manufacturing facility where two pieces of pipe are welded together, inspected, coated and shipped to the field for installation. Using double joints in the field effectively cuts the number of field welds in half which greatly improves the schedule and production.
Pipeline inspections utilize a multi-zone inspection technique (PA-AUT) and Time of Flight Diffraction (TOFD) to separate the examination volume into multiple zones which are based on wall thickness and weld bevel geometries.
Each zone has PA-AUT channels dedicated for the detection and sizing of flaws within that specific zone, as well as adjacent zones and USES the TOFD for the inspection of the weld volume.
The PA-AUT and TOFD data is displayed in a strip chart format to enable the operator to make a very quick determination for weld acceptance or the need for repair.
The middle of the strip chart has the TOFD information displayed and it is surrounded by the root and volumetric mapping channels for each side of the weld. Each inspection zone is depicted as its own strip chart and from the middle outwards depicts the root through the weld cap for the full length of the weld.