On the bounding of pipe bend flexibility factors

Abstract Previously published theoretical work on pipe bends or pipework systems has tended to overlook the fact that resulting deformations as obtained from energy analysis can frequently be shown to be upper or lower bounds on the exact answer. The conditions for bounding are discussed in a simple way within the framework of the theoretical analysis for pipe bends. Upper and lower bound analyses, both more direct than previous analyses, are presented for a smooth pipe bend and the resulting flexibility factors shown to be true bounds. Earlier work is reviewed in the context of the paper and classified into the above two categories where applicable. Some analyses require slight modification before they can be regarded as true bounds.