Oxyacetylene equipment procedure

When using oxyacetylene equipment for welding you should:

• always wear protective eyewear
• wear the proper welding mask or goggles
• wear a welding jacket, welding gloves, long sleeve shirt, long pants and leather shoes
• wear head protection as sparks can burn your hair
• always wear the proper shoes; never sandals, as many sparks will drop to the floor when cutting
• read operators manual and risk assessment
• use overhead exhaust fans (if applicable)
• never use the oxyacetylene equipment near anything combustible
• use extreme caution when handling the two tanks, turning them off or on, and setting the regulators
• use caution when lighting the torch, follow the procedures exactly
• never allow an oxygen cylinder to fall over
• always keep the acetylene cylinder in a vertical position never lay it on its side
• clean and prepare materials for welding – if steam is available, use this to remove materials which are easily volatile. Wash with strong soda solution or detergents to remove heavier oils. Note: Chlorinated hydrocarbon solvents must not be used for cleaning prior to welding.

A full oxygen tank holds over 2,000 psi of pressure! If it falls over and the valve breaks open, the tank will become a high velocity missile.

• Always make sure the tank is properly secured to the stand with a chain.
• Always install a protective cap over the valve whenever the regulator is not attached even on an empty tank.
• Never stand in front of the regulator when turning on an oxygen tank. The sudden surge of high pressure could rupture the gauge and cause serious injury. Always stand to one side when opening the tank!
• Turn the oxygen tank valve to the full-on position when using the oxygen.
• After use, always close the oxygen tank valve fully and bleed the gas out of both the regulator and the tank gauge.

Acetylene gas is highly unstable above 15 psi so the gas is stored in the tank as a dissolved liquid in a special material.

• Always make sure the tank is properly secured to the stand with a chain.
• Always install a protective cap over the valve whenever the regulator is not attached: even on an empty tank.
• Never allow the acetylene tank to be in any position except completely vertical.
• Turn the valve on the acetylene tank ¼ turn open when in use.
• After use, always close the acetylene tank valve fully and bleed the gas out of both the regulator and the tank gauge.

• Wear all appropriate welding apparel and safety equipment.
• Keep the area clean and free of grease, oils and flammables.
• Inspect all equipment. The cylinders, welding torches, hoses, valves, couplings, and tip connections must be checked for damage and leaks.
• Ensure the area is well ventilated.
• All surfaces to be welded must be clean, smooth and free from imperfections and foreign matter.
• Turn the ventilators on.
• Secure your metal/project using appropriate clamps, magnets, etc.
• Select the appropriate welding tip size.
• Select the appropriate welding electrode.
• Make sure a welding blanket or fire extinguisher is nearby.
• Report any faults or damage to supervisor.

• Turn the acetylene regulator valve counterclockwise (closed) in case the last person left it in the open position.
• Slowly turn the acetylene tank valve ¼ turn counterclockwise.
• Open the acetylene torch valve slightly – ¼ turn.
• Turn the acetylene regulator clockwise (in) until the gauge shows about 7 psi: you will hear the acetylene gas flowing out. This will give you a “flowing” pressure which is more accurate than a static pressure. Do this quickly for safety and so you don’t waste much gas.
• Turn the acetylene torch valve closed (clockwise).
• Turn the oxygen regulator valve counterclockwise (closed) in case the last person left it in the open position.
• Stand to one side of the oxygen regulator and turn the oxygen tank valve slowly until it is fully open.
• Open the oxygen torch valve ¼ ‐ ½ turn.
• Turn the oxygen regulator clockwise (in) until the gauge shows about 15 psi: you will hear the oxygen gas flowing out. This will give you a “flowing” 22 pressure which is more accurate than a static pressure. Do this quickly for safety and so you don’t waste much gas. 
• Turn the oxygen torch valve closed (clockwise).

• Turn on the ventilators.
• Open the acetylene torch valve 1/8 turn.
• Light the torch with the flint sparker: never use a match or butane lighter.
• Adjust the flame until the black smoke clears up. If the flame jumps away from the tip, reduce the acetylene until the flame is back on the tip.
• Open the oxygen torch valve slowly.
• As you slowly add more oxygen, you will see a cone shaped flame form. Add more oxygen until the cone just disappears. If you add too much oxygen the torch will make a hissing sound. If it does, reduce the amount of oxygen.
• You should now have a “neutral” flame and are ready to weld.

• Turn off the acetylene at the torch valve.
• Turn off the oxygen at the torch valve.
• Close the oxygen tank valve (clockwise).
• Close the acetylene tank valve (clockwise).
• Open the oxygen torch valve (counterclockwise). You will hear the gas purging from both the regulator and the tank gauge. Once both gauges read zero, close the oxygen torch valve.
• Turn the oxygen regulator valve counterclockwise (closed) so it will not receive high pressure when the next person turns on the oxygen tank.
• Open the acetylene torch valve (counterclockwise). You will hear the gas purging from both the regulator and the tank gauge. Once both gauges read zero, close the acetylene torch valve.
• Turn the acetylene regulator valve counterclockwise (closed) so it will not receive high pressure when the next person turns on the acetylene tank.
• Wrap the torch hoses neatly around the cart and carefully place the torch in the cart storage compartment.

The cutting torch is like the welding torch except for the additional oxygen torch valve and the thumb‐operated oxygen valve.

• Wear all appropriate welding apparel and safety equipment.
• Before attempting to cut, clean the plate of dirt, paint, grease, oil, mud, mill bloom or scale and rust.
• Attach the oxyacetylene cutting torch to the base handle.
• Open the oxygen torch valve (nearest the hoses) to full open – (counterclockwise). Leave this open for the remainder of the use.
• Make sure the other oxygen torch valve (nearest the tip) is closed.
• Follow the directions for the regular welding setup but use the oxygen torch valve nearest the tip for all the adjustments: leave the oxygen torch valve nearest the hoses in its fully opened position.
• When attempting to cut steel, wait until the torch has just started a liquid steel puddle before pushing the oxygen thumb valve. The pressure settings will vary according to the thickness of the steel but start with 8 psi acetylene and 25 psi oxygen.

• Clean joint surface areas of oil, grease, or oxide contamination. Surfaces can be cleaned by brushing with a stainless steel wire brush or by rubbing firmly with emery cloth.
• If oil or grease is present, clean with a commercial solvent. Remember to remove small foreign particles such as emery dust, by wiping with a clean dry cloth. The joint surface must be clean.
• Cut the tube end square, deburr, and clean the surface with a light grade emery tape.
• Push the tube tightly into the fitting or the expanded end of the other tube and apply heat.
• Apply heat uniformly to both tube and fitting by moving the torch around the object to ensure even heating before adding the silver solder.
• As the heated area gradually changes colour to bright red, apply silver solder by lightly brushing the tip of the stick on the joint.
• If sufficient heat is applied the solder should melt on contact and flow into the capillary space between the tube and the fitting, keeping a cherry red colour without overheating the tube.
• As heat is applied evenly around the joint, the molten brazing alloy will be drawn in by “capillary action”.
• To complete the joint, an even build-up of solder should be just visible.
• Remove the heat, taking care not to disturb the joint until the molten brazing alloy solidifies.
• To braze a joint upside down, follow the same procedure, but concentrate more heat on the fitting than the tube. This will draw the molten brazing alloy upwards into the joint.

The method for brass joints is similar to copper jointing, only more heat should be concentrated on the brass initially to bring it to temperature.

• You need to use a nonaggressive, water soluble flux.
• Use a brush or clean rag to apply a small amount of flux to the end of the tube and to the inside of the fitting (most plumbers use the welding rod to apply the flux).
• Avoid overloading the joint with flux as the residue needs to be removed on completion of the joint.
• Care should be taken not to overheat the fitting.
• Have a bucket of water nearby.
• Use an inspection mirror to see that the brazing has flowed completely around the joint.
• Place non-combustible material, e.g. sheet metal or villa board against any surface that could be damaged.