L30050 Feasibility of Basing Natural Gas Pipeline Operating Pressure on Hydrostatic Test Pressure

This report presents the results of a study to determine whether natural gas pipeline operating pressure could be based on some percent of hydrostatic test pressure versus the currently used percent of specified minimum yield strength. The study included the following:

• A study of hydrostatic testing techniques;
• Analysis of hydrostatic test data of many thousands of miles of pipe tested to actual yield in the field and analysis of the operating experience of these lines;
• Results of full-scale experiments to study the relation between flow size and failure pressure;
• Results of investigation of the behavior of defects in a yield environment; and
• Compilation and appraisal of important factors necessary for evaluating the feasibility of basing operating pressure on the hydrostatic test pressure.

Analysis includes an assessment as to if it is both technically feasible and desirable to set the allowable operating pressure as a percentage of the hydrostatic test pressure level.