INTRODUCTION
The Pipeline and Hazardous Materials Safety Administration (PHMSA) has recently proposed a “Draft Integrity Verification Process” (IVP), part of which requires hydrostatic testing to establish the maximum allowable operating pressure (MAOP) and verity the integrity of pipelines that were either not tested after construction or for which such tests cannot be reliably confirmed. This study reviews pipeline incident data and fracture mechanics models that may support limited exemptions or alternative measures from the requirement for hydrostatic pressure testing to 1.25 times the MAOP in order to assure the stability of pipe manufacturing or construction related features. This study was performed at the joint request of the Interstate Natural Gas Association of American (INGAA) and the American Gas Association (AGA).
