Pipeline Safety: Class Location Change Requirements

PHMSA is updating its regulations to allow operators to apply modern risk management principles in addressing the safety of gas pipelines affected by class location changes. Relying on an approach originally developed in the 1950s, PHMSA's regulations use class locations to provide an additional margin of safety in the design, construction, testing, operation, and maintenance of gas pipelines based on population density. When the class location of a pipeline changes due to an increase in population density, an operator may need to take certain actions to confirm or to revise the maximum allowable operating pressure of a segment. Because the methods traditionally used for that purpose do not account for modern risk management principles, PHMSA has granted special permits for more than two decades allowing operators to use an integrity-management-based alternative. This final rule adopts that `IM alternative' by regulation to provide operators with an additional method for confirming or restoring the maximum allowable operating pressure of certain eligible segments that experience class location changes.