Abstract: A method of repairing an under water pipeline from which a defective or damaged length of pipe has been cut away to form longitudinally spaced-apart, exposed, pipe ends which method includes the steps of:(a) butt-welding to each exposed pipe end a tubular end portion of a hollow, open-ended member having an inner or outer part-spherical mating surface;(b) butt-welding a sleeve to one end of a length of replacement pipe;(c) mounting on the sleeve a tubular end portion of a hollow open-ended member which has a part-spherical mating surface complementary to that of one of the open-ended members butt-welded to the exposed pipe ends and which is adapted to form therewith a ball-and-socket coupling;(d) welding to the other end of the replacement pipe a tubular end portion of a hollow open-ended member which has a part-spherical mating surface complementary to that of the other of the members butt-welded to the exposed pipe ends and which is adapted to form therewith a ball-and-socket coupling;(e) positioning the re

Abstract: A process for arc welding in an underwater environment wherein a welding chamber is positioned adjacent a workpiece and an arc welding torch is positioned therein. A gas under pressure is introduced into the chamber to displace the water and a gas is supplied to the torch at a pressure greater than the pressure of the gas in the chamber.