Novel design for PIG to eliminate the effect of hydraulic transients in oil and gas pipelines

Hydraulic Transient is one of the most destructive effects in oil and gas pipelines. Currently existing pigs are one of the main sources for this phenomena due to their physical characteristics and function. In this study, by implementation of a new design to the system of pigs, which utilizes the free spaces surrounding the robot, the effect of hydraulic transient is fully eliminated. To demonstrate the practicality and significance of this study, several various simulation experiments such as laminar flow, pressure distribution, velocity variations and stress analysis are conducted on the new design with adjustable arms as well as the former design utilizing sealing disks. The benefit of using adjustable arms exceeds the goal of this research and makes the design extremely versatile by giving it the ability of multi-diameter pipeline inspection and speed maintenance to derive highest resolution for inspection sensors.