Pressure Swing Absorbers (PSAs)

A leading petroleum company avoided extremely dangerous outcomes by performing thorough, proactive robotic inspections.


inspection cost savings vs. traditional AUT


million UT data readings


decrease in total inspection time


  • PSAs are prone to cracking due to extreme pressure swings
  • The adsorption process can be dangerous and cause failures if the damage goes undetected or unaddressed
  • This refinery typically inspected the PSAs using manual methods, which require scaffolding, adding additional cost, time, and safety
  • Routine high-resolution inspections are needed to monitor the progression of damage growth accurately, making inspection repeatability


  • Full-coverage phased array corrosion mapping via Rapid Automated Ultrasonic Testing (R-AUT) 
  • Full-coverage weld inspection using Automated Phased Array Ultrasonic Testing (PAUT) 
  • High-definition corrosion mapping and weld scan data visualizations with expert analysis


  • Inspection completed at a 25% cost savings compared to traditional AUT
  • In-depth, full-coverage corrosion mapping and weld inspections for 6 PSAs measuring 9’ diameter x 15’ 8” height (2.7 m x 4.8 m) per vessel
  • Total inspection time decreased by 75% compared to conventional manual inspections, with full-coverage scans completed in 1.5 shifts per vessel for a total of 9 shifts
  • The use of automated robotic crawlers eliminated the need for scaffolding access
  • 42 million UT data readings per vessel obtained via Rapid AUT to create data-rich visual maps in .04” x .04” (1 mm x 1 mm) grids compared to traditional AUT in 0.10” x 0.25” (2.54 mm x 6.35 mm) grids
  • The robust data sets revealed that there wasn’t any damage present in the base metal and welds of the PSA vessel

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