Principles of Operation:

There are two operations in gas cutting. A heated flame is directed on a metal to be cut and raise it to bright red heat or ignition point. After that a stream of high pressure oxygen is directed onto the hot metal.

The oxyfuel gas cutting procedure employs a torch with a tip (nozzle). The functions of the torch are to generate preheat flames by mixing the gas and the oxygen in the accurate proportions and to supply a concentrated stream of high purity oxygen to the reaction zone. The oxygen oxidises the hot metal and the melting point of this oxide is well below the iron, so this oxide is melted instantly and blown away by the oxygen stream from the joint. The cutting torch mixes the oxygen and fuel for the preheating flames and aims the oxygen jet into the cut. The torch cutting tip has a number of preheat flame ports and a centre passage for the cutting oxygen .The preheats flames is utilized to heat the metal to a temperature where the metal shall react with the cutting oxygen. The oxygen jet quickly oxidises most of the metal in a narrow section to make the cut. Molten metal and metal oxides are expelled from the cut by the kinetic energy of the oxygen stream. By moving the torch across the work piece at an appropriate rate produces a continuous cutting action. The torch might be moved manually or by a mechanised carriage. The accuracy of a manual operation based largely on the skill of the operator. Generally, mechanised operation enhances the accuracy and speed of the cut and the finish of the cut surfaces.