Abstract: This paper introduces the general layout, basic design and detailed design results of the pipe rack on a super large FPSO, and analyzes the requirements of the Oil Company's General Specifications and Classification Society's Rules for the structural design of pipe rack and hull stool. The influence of the longitudinal bending of FPSO hull on the boundary condition of hull stool is taken into account in the structural design of pipe rack. Transverse pin connection is set between the pipe rack and the topside module to control the weight of the pipe rack and the hull stool with the aid of the transverse support stiffness of the topside module. In the engineering design of FPSO, the quantitative risk analysis of oil and gas leakage and deflagration chain hazards of the topside module is carried out, and the design explosion overpressure of the pipe rack and hull stool is determined. The strength of the hull stool of pipe rack and FPSO main deck under blast accident is analyzed by using the finite element method. Based on the simplified fatigue analysis method and spectral analysis method of cumulative fatigue damage, the fatigue life of the hull stool of pipe rack is predicted.

Key words: FPSO, pipe rack module, hull stool, structural analysis, explosion, fatigue