摘要 |
A method for improving or increasing the strength of a multiple-layer shell type cylindrical pressure vessel, the shell of which, due to the inner pressure applied, tends to present a sine-curve like bending behavior, i.e., a series of continuous curvatures appearing alternately on the opposite sides in the shell, with respect to the neutral line of the bending curvatures. (The intersecting point of such a curvature of bending with said neutral line will be referred to as a bending-direction transition point hereinafter.) The method provides at least one of such transition points a circumferential weld extending throughout the wall thickness of the shell or provides a solid wall type shell section extending from the joint between the head plate and the shell to the first transition point or provides a solid wall type shell section between the two transition points, thereby increasing the bending rigidity or strength at such transition points for the cylindrical pressure vessel. |