Utilizing On-Stream Inspection Techniques in the Petroleum/Petrochemical Industry in Lieu of Internal and Turnaround Inspections

This is part three of a three part article for the IJ describing some of the advanced on-stream inspection (OSI) methods available for use in inspection of pressure equipment in the petroleum and petrochemical industry. These methods can be used, under the right circumstances, to supplement or in lieu of invasive and turnaround inspections, usually at much lower cost. Cost savings associated with using OSI techniques in lieu of internal inspections may include lower total inspection costs, lower turnaround costs, avoiding lost production opportunities, and avoiding vessel cleaning and decontamination costs. On-stream inspection also avoids the safety hazards associated with confined space entry of vessels. However, to achieve these savings and benefits, and still maintain high levels of pressure equipment integrity, the owner-user must understand the technologies in order to intelligently select, apply and interpret the results of these nondestructive evaluation (NDE) methods.

In part one of the article, we covered some pit-falls and precautions when using OSI techniques in lieu of internal inspections. Parts 2 and 3 of this article, provide some information on the main types of OSI techniques available, along with their advantages, disadvantages and relative cost. In part 2, we covered six OSI techniques gaining acceptance in the industry including: ultrasonic guided waves for piping inspection, pulsed eddy current for metal thickness inspection, electrical pulsing technique for piping inspection, real time radiography for corrosion detection in piping, EMAT’s for on-stream piping and vessel inspection and In-service robotics for atmospheric storage tank inspection.