Abstract: Buried tanks usually need multiple openings in the manhole cover on the top of the tanks in order to meet the needs of process pipe connection, which places higher requirements on the calculation of the opening reinforcement of the flat cover and the arrangement of nozzles. Currently, there are certain problems in the design of multiple openings for flat cover by adopting GB/T 150.3—2011. Based on the finite element method, this paper establishes a complete model of bolted connection flat cover, studies the strength and sealing of the structure under different parameters, and discusses the design of openings and the arrangement scheme of nozzles. The results can provide reference for the relevant design.

Key words: bolted connection, opening reinforcement of flat cover, multiple openings, finite element method/FEM