METHODS FOR MANUFACTURING LARGE-DIAMETER CYLINDRICAL TANKS, METHODS FOR MANUFACTURING LARGE-DIAMETER CYLINDRICAL TUBES FOR MARINE ENGINEERING, AND TANKS AND TUBES PRODUCED BY THIS METHOD

Abstract

The invention relates to a method for producing large-diameter cylindrical tanks, a method for producing large-diameter cylindrical pipes for marine applications, and tanks and pipes produced by such method, wherein the method for producing large-diameter cylindrical tanks according to the invention includes: a plate production step to produce single-pipe plates by welding multiple unit steel plates so that the long edges of the rectangular unit steel plates are joined and fitted together; a bending step to form a single pipe by bending the single-pipe plate into a cylinder; a single-pipe forming step to arrange the single pipe in a horizontal position so that the longitudinal weld formed in the single pipe is bent into an elongated cylinder in a horizontal position and the single pipe is finished by welding the longitudinal weld; a ring frame assembly step to assemble one or more rings inside the single pipe to closely contact the inner circumferential surface of the single pipe to support the single pipe;and the hemispherical end assembly step involves assembling the hemispherical end at the tip of the single pipe to close this end. Accordingly, because multiple unit steel plates are welded and pre-assembled to a length corresponding to the circumference of the tank or large-diameter cylindrical pipe being produced and then bent, the number of bending operations can be significantly reduced, thereby improving productivity.