Oxy-fuel welding and cutting: Encyclopedia II - Oxy-fuel welding and cutting - Setting up the equipment

Oxy-fuel welding and cutting - Setting up the equipment

When using fuel and oxygen tanks they should be fastened securely to a wall, a post or a portable cart in an upright position. An oxygen tank is especially dangerous for the reason that the oxygen is at a pressure of 21 MPa (3000 lbs/in² = 200 atmospheres) when full and if the tank falls over and the valve strikes something and is knocked off, the tank will become an unguided and unpredictable missile powered by the compressed oxygen. It is for this reason that an oxygen tank should never be moved around without the valve cap screwed in place.

Never lay the acetylene tank down while being used, as the acetone would start to come out through the valve. If it was laid down while being transported, it must be set upright, valve on top.

After the oxygen tank is securely fastened, remove the valve cap. With the valve opening pointed away from the welder, open the valve slightly for just a moment and then close it. This serves two purposes. For one, it blows out any dirt or dust that may have settled in the valve. This dirt would otherwise end up in the regulator and shorten its life and accuracy. For another, when a tank is filled, the worker has a tendency to tighten the valve securely to make certain it is closed completely. It is better to break it loose now than when the regulator is in place. Attach the oxygen regulator and tighten the nut. Never use pliers, as the pliers will soon damage the brass nut; always use a wrench. Also, there is a tendency of welders to overtighten the nut. If it is not leaking, then it is tight enough. If a great amount of torque is needed to stop it leaking, or if it will not stop leaking in spite of any amount of tightening, then there is something wrong with the nut, the gasket or the valve.

Attach the fuel regulator to the fuel tank in the same manner. The nut on the fuel regulator usually has left hand threads.

Attach the flexible hoses from the regulators to the torch. The oxygen hose is usually colored blue (green in the US) and the fuel hose red. The fuel hose has left hand threaded connectors at both ends and the oxygen has right hand threaded connectors.

With the valves on the torch closed, and the knobs on the regulators screwed out until loose (0 setting), open the valves on the fuel and oxygen tanks. Open the oxygen valve slightly and then wait while the high pressure gauge on the regulator stops rising. Then open the valve fully, until it stops turning. This is a back stop valve. Turning the valve all of the way out prevents leakage through the packing of the valve.

Open the fuel valve also. Only open an acetylene valve one quarter turn. This helps prevent the acetylene from being drawn off too quickly. If acetylene 'bubbles' too rapidly from the acetone, it might become unstable. Open the valve on a LPG tank out completely as on an oxygen tank and for the same reasons.

If there are any leaks in the connections, regulators or torch, or any other faults with the equipment, a safety hazard exists. The equipment should not be used.

Never oil an oxygen regulator. It will cause a fire or explosion — solid brass regulators can be blown apart from the force. Keep oxygen away from all combustibles.

Adapted from the Wikipedia article "Setting up the equipment", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki