Design of subsea and buried LNG pipelines presents challenges such as low operating temperatures (-160°C), multiple pipe walls, and differential expansion of materials. ITP has developed an LNG pipeline design that has been certified by DNV as "Fit for Service" for LNG subsea transport. JP Kenny has developed and applied a comprehensive FE model to ITP's triple-walled (PIPIP) LNG pipeline design to successfully demonstrate the robustness of the pipe design. The FE model is used to determine the displacements and stresses in each of the three pipe walls under all the operating conditions and to provide input data for detailed analyses of the bulkheads, risers, riser supports, and tie-ins to external piping. The basis of the model is presented along with a description of the PIPIP. Typical results of the modeling are presented, which demonstrate how the design of the PIPIP limits the stresses, displacements, and end loads. The use of the model results for design of ancilliary and connecting systems is also reviewed.
展开▼
