Storing and Using Gas Cylinders

If you are making use of a compressed gas cutting torch, then you will need a cylinder of oxygen and a cylinder of fuel gas. Fuel gas is the vapor which actually burns to create the flame coming from the tip of your torch, while the oxygen feed is intended to intensify and stabilize the flame by giving it an oxygen-rich environment, making it burn hotter and faster and allowing the gas to ignite at a lower temperature. The combined flow of these two gases is what allows the cutting torch to function as it does.

There are several different types of fuel gas – acetylene being the most commonly employed due to its flexibility. The flame it produces is suitable for all types of welding and cutting work, as well as softening steel for bending. This flame is mostly used for steel, though it can be used for aluminum if the correct fittings are attached to the torch.

Another widespread fuel gas is propane, which offers more cutting possibilities than acetylene but requires special two-part torch tips and uses twice as much oxygen. Hydrogen’s low heat means that it is frequently employed for welding aluminum, with a special oxy-hydrogen torch, a cobalt lens on the welding helmet window to provide better flame visibility, and flux-core aluminum filler metal. Finally, an acetylene-propane gas, known as MPS gas, can be used for some purposes, but is only suitable for brazing and heating, since its flame is too feeble to create welds.

Regardless of the type of gas it contains, each cylinder in your possession will have an aperture at its top where you can screw in a regulator, which is basically a tap or spigot that allows the attachment of a pressure gauge and hose. Immediately below this is a wider ring of threading, which allows a protective cap to be screwed on when the regulator is not in place, preventing leaks. A cylinder of gas should never be without either a regulator or a cap at any time, even when it is empty.

The hoses and regulators for oxygen and fuel cylinders are made differently so that incorrect linkages cannot be made. Oxygen regulators and hoses tighten counter-clockwise, while fuel gas fittings tighten clockwise. By law in the United States, oxygen hoses are green and fuel gas hoses are red – a system designed to be easy to remember because of its resemblance to green and red traffic lights – and because the hoses can only be attached to an appropriate bottle, this is a method of determining the contents of a cylinder even in the absence of a label.

When you are attaching the components of an oxyacetylene torch system, you can make it far safer to use by inserting a “flashback arrestor” between the regulator and the hose, or between the hose and the cutting torch, depending on personal preference. This special one way valve stops gas from flowing back along the lines, greatly decreasing the risk of fire and explosion.