Apparatus method for welding tank sections

Apparatus for internal circumferential welding of abutting tank sections comprising:

• at least three longitudinally spaced rings including a center ring and at least one side ring spaced on each side of said center ring to define a welding cage;
• means for moving tank courses to be welded longitudinally relative to said spaced rings such that their edges are in abutting engagement in the center ring;
• said center ring having mounted thereon a plurality of circumferentially spaced, radially directed center jacks each extendible the same distance regardless of the resistance encountered by a particular jack to force the abutting edges of the tank sections into precise circular cross section and support and hold the abutting edges in alignment during rotation and welding;
• each of said side rings having mounted thereon a plurality of circumferentially spaced side jacks of the seek-and-find type which automatically extend until all jacks exert the same force on the tank sections to support and hold the same in welding position;
• welding means movable longitudinally within the welding cage operative to circumferentially weld the abutting edges within said center ring;
• and means for rotating the welding cage during circumferential welding of the abutting edges.

Apparatus for internal circumferential welding of abutting tank sections comprising:

• at least three longitudinally spaced rings including a center ring and at least one side ring spaced on each side of said center ring to define a welding cage;
• means for moving tank courses to be welded longitudinally relative to said spaced rings such that their edges are in abutting engagement in the center ring;
• said center ring having mounted thereon a plurality of circumferentially spaced, radially directed mechanical jacks each extendible the same distance regardless of the resistance encountered by a particular jack to force the abutting edges of the tank sections into precise circular cross section and support and hold the abutting edges in alignment during rotation and welding;
• each of said side rings having mounted thereon at the bottom at least one mechanical jack for raising and lowering tank courses, and a plurality of circumferentially spaced hydraulic jacks of the seek-and-find type which automatically extend until all jacks exert the same force on the tank sections to support and hold the same in welding position;
• tank engaging means on said hydraulic jacks to facilitate clamping of tank courses;
• welding means movable longitudinally within the welding cage operative to circumferentially weld the abutting edges within said center ring;
• and means for rotating the welding cage during circumferential welding of the abutting edges.

A method of circumferentially welding a pair of hollow tank sections of generally circular cross section in end-to-end abutting relation to form an elongated tank comprising:

• providing three longitudinally spaced, axially aligned, rotatable rings including a center ring and a pair of side rings on either side of said center ring;
• the center ring including a plurality of circumferentially spaced, radially directed center jacks each extendible the same distance regardless of the resistance encountered by a particular jack to force the abutting edges of the tank sections into a precise circular cross section and support and hold the abutting edges in aligned relation during rotation and welding;
• the two side rings including circumferentially spaced radially directed side jacks of the seek and find type that will automatically extend until all jacks exert the same force on the tank sections extending from each side of the center ring to thereby support the tank sections for rotation about the common axis of the three rings;
• longitudinally aligning first and second tank sections to be welded such that the ends of the first and second tank sections to be welded abut in said center ring;
• clamping the abutting edges of the first and second tank sections together with said center jacks, thereby forcing the abutting edges into mating circular configuration;
• clamping the first and second tank sections respectively in said side rings with said side jacks to support the tank sections about the common axis of the three rings;
• moving welding equipment longitudinally within one of said hollow tank sections to a point within said center ring adjacent the abutting edges;
• rotating said center ring and said side rings with the abutting tank sections clamped therein;
• and welding the abutting edges together as said tank sections are rotated.