Oxy-fuel Cutting and Welding Machines

Oxy-fuel cutting machines and oxy-fuel welding machines use fuel gases and oxygen (e.g., oxyacetylene ) to cut or fuse metals by generating a high temperature (980-degree C) torch flame. Oxyacetylene cutting, as this process is known, mixes a stream of pure oxygen with acetylene, hydrogen, liquefied petroleum gas (LPG), natural gas, propane, propylene, or LPG and methylacetylene-propadiene (MAPP). The fuel gas is mixed with oxygen inside a cutting torch to produce a high-temperature flame. Oxy-fuel cutting machines have a cylinder, connection and check valve for the fuel gas; a cylinder, connection and check valve for the oxygen; and an angled mixing chamber where the fuel gas and oxygen are mixed. A regulator controls pressure from the tanks while a flashback arrestor or non-return valve prevents the mixture from returning to either cylinder. The cutting torch’s trigger forces oxygen down a third connection and towards the workpiece, causing the metal to burn and the resulting molten oxide to exit the other side.

Oxy-fuel cutting machines carry product specifications such as fuel gas, regulator type, and hose style. Acetylene, a colorless gas made of carbon and hydrogen, is the most common fuel source. When burned with oxygen, acetylene can produce a flame between 5700 and 6300 degrees F. Oxygen, a nonflammable gas that supports combustion with other elements, is obtained by liquid-air or electrolytic processes and stored in steel cylinders. There are two types of regulators for oxy-fuel cutting machines: single-stage and double-stage. Single-stage regulators produce a total pressure drop in one stage. Double-stage regulators produce a total pressure drop in two stages. With both types of pressure regulators, blowout disks or spring-loaded relief valves are used. In terms of connections, most oxy-fuel cutting machines use twin or double hose that joins the fuel hose and the oxygen hose side-by-side.

Although there are several different torch styles for oxy-fuel cutting machines, most devices feature a trigger-style mechanism. Typically, the flow of high-pressure oxygen is controlled by a valve on the side of the torch. Torch tips are designed to produce an even flow of gas without overheating. Seats must produce leakproof joints so that preheat gases do not mix with the oxygen or escape into the atmosphere. Accessories for oxy-fuel cutting machines include cleaners, clamps, cylinder trucks, and holding jibs. Welders should wear personnel protective equipment such as goggles, gloves, and leggings.

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