Optimisation of Heat Pressure Welding of Steel Wire in Flexible Riser Manufacture, Applying Taguchi Design-of-Experiment Approaches

Abstract

The safety, quality and overall integrity of flexible risers has a high dependence on the robustness of joining processes used in their manufacture. One such process used in this industry is the heat–pressure welding process, used in the joining of high tensile steel wires. The optimisation of such welding processes now demands that a statistically–valid and systematic approach be taken. The application of Taguchi methodology to the welding of high tensile steel wires described in this paper is a relatively new departure for Wellstream Flexibles. This paper describes the approaches taken to optimise the heat pressure welding of new steel grades in this demanding application, and the subsequent confirmation of the optimised parameters in real–world environments. Quality response factors are defined and analysed for welds in a range of carbon steel wire materials, leading to the subsequent optimisation of target quality for the manufacture of flexible riser pipe.