Method and apparatus for resistance butt welding under water

Abstract

Abstract 1,080,410. Welding by pressure. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. Nov. 22, 1965 [Nov. 24, 19641, No. 49510/65. Heading B3R. In resistance butt welding the ends of metal members under water the ends are clamped together by a clamping device to form a closed conductive path including the device and the ends and an induction system is inductively coupled to the path to heat the ends and weld them together. Steel pipes 10, 11 to be joined underwater are held abutting by a metal clamp 13 consisting of a pair of slidably engaged elements 14, 15, a shaft 16 on the element 15 fitting slidably in a bore in the element 14 and an electrical mechanical or hydraulic actuator 20 being connected to the free end of the shaft 16 to bring the elements 14, 15 together. The hinged gripping parts 21, 22 of the elements 14, 15 encircle the pipes and surrounding a part of the clamp is a toroidal magnetic core 27 having a multi-turn winding 28 thereon connected to a high voltage supply source 31 located on a strip 32. Current supplied from the source 31 induces a current in the clamp and ends and most of the heating effect is produced at the abutting ends to weld them. An inverted chamber may be placed over the weld area so that steam generated will displace water in the chamber but preferably a non-conducting, e.g. plastic sleeve 34 is provided to fit loosely over the pipe ends to restrict flow of water. A bored non-conductive, e.g. ceramic plug may be provided in the pipe ends and is knocked out after welding or melted out if of suitable matonal. Rods or plates may be similarly welded.

Inventors

• 👤 Robert H Kolb

Bibliographic Details