To evaluate the future application of X80 steel pipe in high-pressure oil and gas pipelines in China, hydrostatic burst tests were performed. The deformation and yield strength of longitudinal submerged arc-welding steel pipe Phi 1016 x 18.4 mm under five applied pressure levels were measured. When the hoop stress is lower than 1.1 SMYS, the pipe normally deforms elastically and uniformly with the maximum strain less than 0.3%. The slope offsets of the pressure-volume plot of pipe were discussed. (C) 2009 Elsevier Ltd. All rights reserved.