A North American operator required inspection of a liquid propane line critical to the company’s business. This 6" thin-walled liquid propane line is an extremely difficult environment for conventional ultrasonic inline inspection (ILI) methods.

The medium’s volatility can cause variations in sound velocity from 1,520 mph (680 m/s) to as high as 2,235 mph (1000 m/s), depending on pipeline pressure and temperature. This large swing degrades the accuracy of ordinary tools and can render them ineffective.

• High-accuracy inline inspection revealed hundreds of crack-like anomalies requiring operator attention. Most of these were lack-of-fusion defects typical in long-seam ERW pipe. Nearly 100 dents were also reported. All of the reported crack-like and crack-field features were calculated in absolute depths. Inspection accuracy was confirmed by the unity plot, which showed a 97% correlation of field investigation and inspection results.

• NDT Global provided the operator with a comprehensive, on-time, post-inspection Pipeline Integrity Assessment that included a detailed, in-depth analysis of data collected from the ILI run, as well as insights to pipeline condition, repair, and maintenance. Proven, proprietary algorithms maximized data accuracy.

• Close correlation of field investigation and inspection results, along with insights from NDT Global enabled the operator to design and implement a more aggressively proactive pipeline integrity management program. This inspection enabled the operator to substantially reduce ongoing operational risk.