Structural Analysis of Cryogenic Flexible Hose

Abstract

Significant gas resources remain to be developed in remote offshore locations. These resources can be produced through the use of a floating liquefied natural gas plant (FLNG) and exported through liquefied natural gas (LNG) carriers. Cryogenic flexible hoses provide a structurally compliant solution for the transfer of LNG between the FLNG and LNG carrier in harsh offshore environments. One of several cryogenic flexible hoses currently being developed in the industry is a structure composed of several layers; a corrugated stainless steel pipe in pipe structure reinforced using two layers of armoring wires. Thermal insulation of the inner hose is obtained by creating a vacuum in the annulus of the pipe in pipe. To ensure sound structural performance and integrity of the flexible hose during offloading operations, a Failure Mode and Effects Criticality Analysis (FMECA) was performed. 3D finite element models of the fully assembled hose and selective individual components were generated to assess their structural response to different loading scenarios, resulting stress concentrations and layer interactions. A sensitivity study of the corrugation profile of the corrugated pipe was performed to minimize stress concentrations and allowable bending radius.