What is underwater cutting?
Underwater cutting is a technological process. The oxy-arc principle is used to cut steel and non-ferrous metals with this technical technique. It cuts with pressurized oxygen flowing through a tiny hole in the center of a conventional thermic electrode. The oxygen stream induces rapid oxidation of the electrode material, which generates heat for cutting the metal.
How does underwater cutting occur?
The torch’s negative (-) pole is powered by a D.C. generator, and the metal to be cut is connected to the positive (+) pole via a particular sort of earth. A thermic electrode holds the torch’s head in place. Collets hold the electrodes in place in the head. The electrode diameters range from 4 to 48 millimeters. To expel the stub, just twist the torch grip to clamp and release the collet.
A high-volume regulator on the oxygen cylinder, fed by a manifold, allows for unrestricted flow regardless of pressure. Suitable valves and washers, as well as replaceable flash arrester screens, keep water from getting into the torch’s head.
Things to observe while underwater cutting
Underwater, a diver wears a helmet-mounted eye shield with the right lens installed while working. There should be no combustible or explosive materials near the place where cutting and welding are to be performed, and no oil or grease should be used on the equipment.
Whenever the diver-welder is working, he or she must face the earth connection so that the cutting takes place between them. When the electrode is reduced to a 75-mm stub, the diver should open the safety switch and signal the surface crew to shut off the current. By doing this, the collet is unfastened by rotating the wrist while pressing the oxygen lever. The tube is then released from its container.
Precations during underwater cutting
Oxygen quickly oxidizes combustible materials, and because grease and oil are combustible, this oxidation reaction produces so much heat that the materials can be ignited, resulting in fire or explosion. It’s always risky to make cuts in tight quarters. Oil, grease, and other combustible materials should be kept well away from cutting and welding areas to avoid the spread of fire and explosions.