Pipeline Girth Weld Inspections Using Ultrasonic Phased Arrays

Abstract

Automated ultrasonics (AUT) is more reliable, faster, has better detection of critical Lack of Fusion defects in pipeline construction welds, and poses no safety hazard compared with radiography. Phased arrays also present major improvements over conventional multiprobe ultrasonics, both for onshore and for offshore use. Probe pans are lighter and smaller, permitting less cutback; scans are quicker; phased arrays are considerably more flexible for changes in pipe dimensions or weld profiles, and for different scan patterns; phased arrays can perform "specials", such as inspecting seamless pipe of variable wall, clad pipes, thick and thin sections, and use automated set-ups. This paper describes the PipeWIZARD ultrasonic phased array system for girth weld inspections, track record and acceptances, and some of the special applications. These include:• Compensating for variations in seamless pipe wall thickness.• Wedge temperature compensation.• Premium inspections for risers, tendons and other components.• Small diameter pipes.• Multiple displays.• Clad pipe.• Portable phased arrays for tie-ins and repairs.• Improved sizing approaches.

The Effect of Phased Array Parameters on the Detecting Accuracy of Welding Discontinuities and 3D Measurement

“…Using signals from a PAUT probe, the length of the discontinuity was measured by moving from the point yielding the maximum echo amplitude to 50% or ½ (6 dB). The length of each defect was additionally calculated for each drop method (6 dB, 12 dB or overall) as shown in table (1). By using the results, the method used to assess the discontinuity length of the welds was analyzed.…”

“…Phased array has developed well in the last several years, particularly for weld inspections to overcome the limitations of radiography inspections, and the importance of ultrasonic is rapidly replacing radiography worldwide especially automatic ultrasonic test (AUT) used phased arrays technique as the latest development in AUT and present major improvements over conventional multiprobe ultrasonics for gas pipeline girth weld & pressure vessel inspection respectively as reported by Michael and Ginzel [1], Moles and Noel [2].…”

Special Phased Array Applications for Pipeline Girth Weld Inspections

“…These features are defined by ASTM E-1961-98 [6]. R/D Tech has a commercial phased array system, PipeWIZARD [7], which can also meet or exceed any of the other codes -API 1104, DNV OS101, ISO 13847 [8][9][10].…”