Unless pipelines are shut down immediately after a rupture, the damage that occurs as a result could be catastrophic.
Most of the large liquid pipeline operators have leak detection systems that are designed to detect ruptures. However, investigation of past ruptures indicate that the overall low reliability of many of these systems may have been the reason for delayed detection and response times of past rupture incidents.
Extensive false leak alarms may have soured controllers’ confidence in leak detection systems, in turn causing them to ignore the real rupture alarms or pay them insufficient attention. Some experts have suggested that in by focusing on detection of very small leaks, the pipeline industry has diminished its ability to detect ruptures.
Leaks and ruptures should not be considered in the same class of pipeline failure. When a pipeline ruptures, the volume of escaped fluid can be unavoidably large, even if detection, response and containment are performed quickly. Thus, a rupture alarm should not be treated like a leak alarm and, arguably, rupture alarms should trigger an immediate shutdown of the respective pipeline.
Robust rupture detection is not easy given the challenges; diversity of pipelines, varying operating scenarios, changes in pump and valve status and the need to detect and alarm a rupture quickly.
In API RC 1175, which addresses pipeline rupture detection in company leak detection programmes, companies who have not already done so will need to review their rupture detection methods in the near future.
Independent systems detect ruptures with high reliability. A false alarm rate of less than 1 per year will improve the confidence of the pipeline controllers, assuring that they respond quickly to a rupture event. An ultimate goal of the industry is to automate the response to alarms using a highly reliable rupture detection system.
Developing a successful rupture detection system demands considerable capital expenditure and many in-house resources. It requires pipeline data from both ruptures and normal operations. The rupture detection system must also be tested with years of pipeline data to verify a high reliability and with historical data from real ruptures, and, finally, with simulated rupture data. Companies that have developed SCADA-based rupture detection systems in-house report that these systems cannot guarantee detection of ruptures that occur over 10 - 12 miles downstream of a pump station.
As developers of the first ever commercial statistical leak detection systems and with expertise in applying pattern recognition in pipeline leak detection, Atmos International is hoping to deliver the best rupture detection system.
In rigorous testing, the Atmos Rupture Detector detected every rupture (regardless of its location) along the pipeline, while maintaining high reliability with false alarm rate of less than one per year.
Atmos’ detector can be quickly installed on pipelines, without the need to have an Atmos leak detection system already.
Read the article online at: https://www.worldpipelines.com/product-news/14122016/atmos-to-enhance-pipeline-rupture-response/