This website is right now being updated. Some of the content might still refer to ptc 2019.
The operating conditions of gas distribution pipelines are not always suitable for running conventional in-line inspection tools, particularly due to extremely low or high gas speeds and/or extremely low pressures. In case conventional inspection tools are run through these pipelines, the tools are at risk of becoming lodged, or the recorded data is often of poor quality due to an unstable velocity profile. Thus, a different pipeline specific inspection approach is required to be able to record high-quality inspection data in such pipelines. Recently, new developments in in-line inspections have made it possible to inspect pipelines that have high/low flow or low pressures. In these inspection programs the complex operating conditions, inspection requirements and pipelines details have to be fully analyzed and understood to be able to provide solutions which ensure that high-quality inspection data will be recorded during the inspection. In this paper, the newest services and solutions to inspect gas distribution pipelines with extreme operating conditions are described in detail. Several case studies are presented which illustrate that these pipelines can be inspected without the need to change the operating conditions. The first case describes the inspections of distribution lines which have pressures of less than 10 bar. The second case describes the inspection of a distribution line which has gas speeds as low as 0.01 m/s. Lastly, the third case describes the inspection of a 20” distribution line which has gas speeds of up to 7 m/s.