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Piping ball joints, flexible hoses, and swivel arms can also involve large displacements which need to be properly accounted for in design calculations.
In addition, P-delta with large displacements enables engineers to more accurately calculate stresses and reactions in layouts where flexible piping exhibits catenary behavior. Following is a simple example illustrating the effects of P-delta with large displacements which users can easily reproduce with their own piping stress program. Pipe section OD 6.625" wall thickness .188", A106-B, fluid contents specific gravity 1.0 (water), no insulation. 80 ft. span of unsupported pipeline divided into 5 ft. segments. Anchors on each end have moment releases with rigid fixity in all 3 translational directions. That is, anchors are rigid in global X, Y, and Z direction with no rotational restraint stiffness.
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