A DEVICE FOR A HYDRAULIC CUTTING TOOL

摘要

A device for a hydraulic cutting tool (30) for cutting of at least one pipe (16, 18, 20) or tubular object beneath a water floor (10), wherein the cutting is carried out from a surface facility (2). The cutting tool (30) is anchored in a pressure tight manner in the pipe (16), whereupon pressurised gas (86) is pumped into a pipe section (80) immediately below the cutting tool (30). With this, liquid (8), and eventually pressurised gas (86), will flow out of the pipe section (80) via a short drain pipe (66) through the cutting tool (30), so as to create a gas filled pipe volume (90) comprising the relevant cutting depth (32) in the pipe section (80). The invention differs from prior art by the outflowing liquid being led onwards up to the surface facility (2) via a drain line (92). The upper end portion of the drain line (92) is connected to at least one adjustable choke device (102, 104). This allows the gas overpressure in said pipe volume (90) to be controlled during the cutting, providing optimal operating conditions during the hydraulic cutting.