Leak detection systems come in many “flavors”, each with distinct advantages, disadvantages and sometimes unique features and capabilities. Needless to say, performance and cost vary greatly as well. It can be a daunting task to decide which technology to invest in for a specific pipeline and a few wrong turns in the decision making process can end up being very costly. It is easy to say “I want a leak detection system capable of detecting a ten gallon spill in less than a minute, locating it within an accuracy of 10 feet”. It might even be possible to install a system that can achieve this, but what about the cost? If this system costs ten times as much as another system with slightly lower performance, is it really worth spending the extra money? What is the difference in the total cost of a specific incident when you factor in the various cost components? This paper puts some of the leak detection metrics and selection criteria into perspective and illustrates the importance of various factors under different conditions. This is accomplished by using some hypothetical, yet realistic, examples of various leak incidents.
American Petroleum Institute’s publication “API RP 1130” provides an excellent overview of most of the leak detection methods available for liquid pipelines – and many of these apply to gas pipelines as well. API RP 1130 also provides a definition of the performance metrics and other selection criteria that should be considered during the selection phase. Sometimes the selection criteria are not carefully considered and prioritized, which can lead to a poorly written Request for Quotation (RFQ) issued to various system vendors. To make matters worse, this is often done using a format that originally was part of API 1155 – now an appendix to API RP 1130.