Emerald Group Publishing Limited
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Kerry cracks NDT for TRW
Kerry cracks NDT for TRW
Keywords: Cleaning, Non-destructive testing
Kerry Ultrasonics has adapted its extensive knowledge of precision cleaning to the field of non-destructive testing (NDT) by supplying an automatic system to Midlands-based TRW Aeronautical Systems, leading supplier of aircraft engine controls to companies including Rolls Royce and Pratt and Whitney. The dye-based system detects cracks in aluminium hydraulic components, the largest of which are 600 × 400 × 400 mm, and many of which are very awkward shapes featuring numerous blind holes (Plate 2).
The automated Kerry machine runs alongside TRW's pre-existing manual NDT process but is said to offer greater flexibility, a consistent quality level and increased throughput capacity. The four-stage plant mainly operates in a single-piece-flow manner, but its Autotrans Mk 4 Major handling system can process up to five parts per basket and more than one basket simultaneously.
Plate 2 Kerry Ultrasonics has adapted its extensive knowledge of precision cleaning to the field of non-destructive testing (NDT) by supplying an automatic system to Midlands-based TRW Aeronautical Systems, leading supplier of aircraft engine controls to companies including Rolls Royce and Pratt and Whitney
Each component is first dipped in penetrant dye and rotated to ensure that the dye reaches every hidden cavity. The second stage comprises an air-agitated immersion rinse sandwiched between spray rinses, to remove all of the dye apart from that which remains inside any potential cracks. The rinse water is drained off to a reservoir for reuse. Next, a vacuum dry completely eliminates excess liquid before the part enters a dust storm cabinet which brings the remaining dye to the surface. When the component is then viewed under ultraviolet light, any cracks are more readily visible.
Kerry and TRW worked together on the 8 month project from the very start, managing to reduce the number of stages required by the system from an initial six. Jim Thomas, project engineer at TRW, describes this consultation as "the epitome of teamwork between two companies."
The proven reliability and quality of the Kerry equipment already possessed by TRW was one factor in the company's choice of eventual NDT-system supplier. However, Jim points to a more general professionalism on Kerry's part. "Kerry are extremely co-operative," he says. "If we've got a query, we just give them a call and they come down."