Rotary abrasive jet cutting tool for radial cutting of submerged metal pipewor k uses inflatable rings for immobilizing inside pipework

摘要

A tool for radial or diametrical cutting of metal pipework 1, in particular submerged submarine pipework and those forming parts of oil platform support structures, the cutting being performed by high pressure projection of abrasive particles suspended in a vector fluid, comprises a body 2 which can be immobilized inside said pipework, and a rotary head 3 provided with a nozzle 5 for projecting a mixture of water and abrasive, said body including a first inflatable positioning ring 6 and a second inflatable positioning ring 7, each of said inflatable rings being toroidal and being constituted by an elastomeric membrane which defines a sealed cavity which is very flattened in cross section when deflated, and which has a thickness under pressure that is at least twice its deflated thickness. Use is for cutting pipework forming the support structures of oil platforms when dismembering or dismantling oil platforms. When the cutting operation is finished, the cutting tool and the cut tube is lifted to the surface by hoist 36 when lifting rings 8, 9 are inflated to cause cushions 38, 37 to bear against the inside wall of the tube. IMAGE