In a two-year program, seventy-eight specimens of PVC pipe with and without adhesive socket joints were tested in a four-point bending apparatus. Internal pressures were varied from atmospheric pressure (0 psig) to the rated internal pressure of 280 psig. Results of the plain pipe are compared to pipe with joints. All testing was done using a special apparatus developed to accommodate the large deformations required for fatigue testing of PVC pipes. This apparatus is described as well as the test results. Both strains and stresses are plotted against cycles-to-failure. Finite element elastic models of the socket joined specimens were analyzed to establish the areas of stress concentration and to explain the observed failures modes.Phase I testing indicated that the pipe internal pressure might have a significant effect on fatigue life. Joined pipe specimens with no internal pressure were weaker in bending fatigue than pressurized pipe. As a result, the internal pressure was systematically varied between 0 psig and the rated pressure 280 psig. Results of Phase 2 testing showed that there is a dependence on internal pressure. Also, the effects of an adhesive primer and roughening the pipe surface on joint fatigue strength were also studied.Strain rate is known to have a large effect on the fatigue of thermoplastic polymers.This effect has not been systematically studied and remains an unknown.This research was supported by two PVRC grants: 96-15 (Phase 1) and 97-13 (Phase 2). A final report on Phase 1 (dated January 21, 1977) was approved as completion of that portion of the project.This report combines the results of Phase 1 and Phase 2 testing of PVC pipe.