A Study on Pipeline Pressure Testing Using Pressure-Volume Curve

The pressure testing of a pipeline is carried out using either of the two methods: ①by controlling the hoop stress of pipeline, or ②by controlling the test pressure according to the pressure-volume curve(PVC) of the test medium. The first method, though quite simple, taking the yield limit of each pipe length as an invariant, most likely results in over-yield or un-der-pressure; therefore it is difficult to maintain the test pressure. This problem can be solved by using the second method, which controls only the linear relationship of PVC and stops pressurizing once nonlinearity occurs in the curve. Studies and statistics show that the higher the test pressure, the more defects can be found in the pipes and the more reliable the pipeline system can be. Discussed in this paper are the application of PVC method in China, which is popularly exercised abroad, the selection of reasonable control parameters, as well as the natural elevation differences among testing sections and the volume control of the test medium.