STEEL-COMPOSITE PIPE APPARATUS AND METHOD OF MANUFACTURING SAME

摘要

A pipe for high pressure pipelines and method of manufacturing same are provided in accordance with the invention. The pipe comprises an inner steel layer and a composite outer layer wrapped in continuous contact around the steel layer. The parameters of the steel and composite layers are optimally selected so that the respective strengths of the steel and composite are fully utilized. The selected parameters include at least the thickness and yield strengths of the respective layers, wherein the thicknesses of the respective layers are selected so that at a maximum internal operating pressure, the circumferential stresses in the pipe are desirably distributed such that the composite layer is at or below a composite design operating stress and the steel layer is at or below a steel design operating circumferential stress. The circumferential stresses are desirably distributed by first determining the appropriate amount of plastic deformation of the steel layer that will produce the desired stress distribution, then autofrettaging the steel layer to obtain the desired plastic deformation.