Engineering and Ultrasonic Tool Run in a Natural Gas Pipeline to Detect SCC

Stress Corrosion Cracking (SCC) is a major integrity threat for many gas and oil pipeline operators. Once SCC is detected on a pipeline, if the severity of the SCC is determined to be class III or IV, it is the operator’s responsibility to ensure that the risk of a SCC failure is adequately mitigated. This paper discusses several design strategies implemented by TransGas for the purpose of this UT ILI run including: designing a custom launcher to facilitate easy insertion of batching pigs, UT ILI tool, and batching liquid; development and use of a flow / speed control system utilizing pressure differential readings from orifice meters, as well as many of the logistical challenges associated with the project.