GB1274886A - Apparatus for remotely joining underwater pipelines - Google Patents

Abstract

1,274,886. Welding by fusion and pressure. SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ N.V. 9 July, 1969 [11 July, 1968; 16 Dec., 1968], No. 34655/69. Heading B3R. [Also in Division F2] Two pipes are joined by remote control on the sea bottom using the following methods. In the first method, Fig. 6, an explosive ring charge is inserted in the end of pipeline 12, and a die 61 is placed over the end. The charge is detonated, causing the pipeline end to expand into the die 61 at 71. A flange 72 is welded on to the end of pipeline 37 prior to clamping in the apparatus 17. A split sleeve 66 is hydraulically clamped over the flange 72 and die 61 and draws the pipeline ends together by means of tapers 74, 65. In the second method, Fig. 10, an expansible metal ring 119, see Fig. 11, is inserted in the end of pipeline 37 prior to clamping in the apparatus 17, and is expanded into engagement with the pipeline ends after alignment. A split sleeve 117, connected to a series of retorts 126 by inlets 127 and to a series of receivers 131 by outlets 132, is clamped over the pipeline ends to form a mould cavity. Air pumped through the mould cavity via inlets 129, by-passing the receivers 126, and out via one-way valves 134 to clean and dry the cavity. Thermit mixtures of preferably iron oxide and aluminium located in the retorts 126 are ignited by charges of preferably peroxides and aluminium dust, ignited by sparks, and when the reaction is completed, the resulting metal is cleansed by fusible plugs 135 from the retorts 126 and flows through the cavity to the receivers 131 initially to preheat the cavity. When the receivers 131 are filled, further metal fills the cavity to effect the weld. Moulded exothermic charges or electrical heaters 138 may be used to preheat the mould. A pressurized feed may be used whereby the retorts 126 and receivers 131 are reversed in positions. The expandable ring 119, backed by inflatable rubber 118, may be of steel or coated with copper or ceramics. The split sleeve 117 may be removed after welding or a one-piece sleeve may be used and left in place.