Behavior of mechanical-bonding double-wall pipe under various loading conditions

A new type of mechanical bonding double-wall pipe produced by shrink-fitting and hydraulic expanding has developed for sour gas service. The behavior of this pipe was experimentally and analytically examined under the following loading conditions: (1) interfacial gas pressure between the inner and outer pipes; (2) bending load; (3) tensile load; and (4) internal pressure. The results revealed no practical problems of using this double-wall pipe. Simple formulas were established for evaluating the critical fracture strength of this pipe under the loading conditions tested, which make it easier to select the double-wall pipe sizes and materials.