Target Reliability Levels for Onshore Gas Pipelines

Establishing target reliability levels that have wide industry and regulatory acceptance is necessary in order to proceed with the implementation of reliability-based design techniques for pipelines. The target reliability levels described in this paper are based on life safety considerations and are applicable to natural gas pipelines. They were calibrated to a series of pipeline designs based on ASME B31.8, using design parameters and operating practices intended to be representative of North American pipelines. The targets define an upper bound to the total failure rate due to failure events involving significant leaks (excluding pinholes) and ruptures. This paper summarizes the results of the analyses undertaken to establish the target reliability levels, provides the target reliability curves developed and presents an approximate analysis of their economic implications.