The process of pigging involves using a pipeline inspection gauge, or PIG. A pig is a device that is pushed down a pipeline to clean the internals of the pipe and measure its wall thickness and integrity. Intelligent pigs use ultrasonic testing and magnetic flux leakage testing to measure corrosion and metal loss. Engineers evaluate the data to determine what scope of rehabilitation is required and where the problems are located.
Trenchlesspedia Explains Pigging
Although “PIG” is an acronym for pipeline inspection gauge, the term is also associated with the squealing sound that the PIG device makes as it passes through the pipe.
As the PIG moves along the pipe, it records measurements using ultrasound and magnetic flux. These measurements give an indication of the integrity of the pipe and highlight potential defects. PIGs can be propelled along the pipe by the product flow, meaning that they can be used while the pipe is in service, making them a valuable tool to evaluate rehabilitation scope without disruption to the product.