USING THE OXYACETYLENE CUTTING TORCH

USING THE OXYACETYLENE CUTTING TORCH For EG243 Welding: Pressurizing Lighting Cutting Shutting Down the Airco 9500 Cutting Torch. Procedure, PowerPoint and pictures by Stephen Collins (scoll@mma.edu) Demonstration by Robert Giffin Click on arrows at top to move to the next page or go back December 12, 2003

SAFETY Do not perform this procedure without supervision by an instructor. Oxyacetylene equipment must be set up in accordance with ANSI/AWS C4.2-90 before beginning. This procedure is only for the Airco 9500 torch with a #144-1 tip. Other manufacturers may require different procedures. Other tip sizes require different pressures (see operator’s manual). Adequate ventilation must be provided to avoid hazardous accumulation of flammable, explosive, and toxic gases.

PERSONAL SAFETY EQUIPMENT Wear: Safety glasses Cotton clothing (no nylon or polyester) Long sleeves and pants Leather boots Leather welding gloves #4 Cutting shield (not shown in this picture)

PRESSURIZING Back out both regulator adjusting “T” handles counterclockwise until they are completely loose

PRESSURIZING Stand aside. Keep your face away from the gauges. Open the oxygen cylinder valve counterclockwise slowly at first. then all the way, tight up against the back seat. The cylinder pressure gauge should show pressure.

PRESSURIZING Open the torch oxygen valve counterclockwise 1/2 turn.

PRESSURIZING Turn oxygen regulator adjusting “T” handle clockwise. Set oxygen gauge working pressure at 30 psi. Oxygen should now be flowing from the torch tip.

PRESSURIZING Purge 5 sec./50ft of hose. Close the torch oxygen valve clockwise.

PRESSURIZING Stand aside. Keep your face away from the gauges. Open the acetylene cylinder valve counterclockwise until the cylinder gauge shows pressure, then another 1/4 to 1/2 turn counterclockwise but not more than 1 full turn total.

PRESSURIZING Open torch acetylene valve 1/2 turn counterclockwise.

PRESSURIZING Provide adequate ventilation to prevent accumulation of flammable gas. Turn acetylene regulator adjusting “T” handle clockwise. Set acetylene gauge working pressure to 4 psi. Acetylene should now be flowing from the torch tip

PRESSURIZING Provide adequate ventilation to prevent accumulation of flammable gas. Purge 5 sec./50 ft. of hose Close torch acetylene valve.

LIGHTING FLASHBACK WARNING: be ready to shut off fuel, then oxygen. Wear shade #4 cutting shield and leather gloves Point torch away from self, cylinders, others, and combustibles Slightly “crack open” the torch acetylene valve

LIGHTING Using only a flint spark lighter, place the lighter near the tip and squeeze. A small, smoky flame should appear at the torch tip.

ADJUSTING Open the torch acetylene valve further until the flame is bright and bushy with no smoke, but the flame is still attached closely to the tip.

ADJUSTING Open the torch oxygen valve slowly until the long, white, feathery flame is replaced by sharp white cones at the tip.

ADJUSTING Depress the torch cutting lever completely. While it is depressed, open the torch oxygen valve further as necessary to get clean, sharp, white cones. Blue cones indicate too much oxygen. Release the torch cutting lever.

CUTTING Hold the torch handle in one gloved hand, rest the torch tubes on the other. Slide torch out to place tip centered over edge of plate, cone tips just touching the steel. When the steel is red hot, squeeze the cutting lever and slide the torch toward you.

CUTTING Move slowly at first, then more quickly to get a clean cut.

SHUTTING DOWN Shut off the torch oxygen valve quickly, then the torch acetylene valve quickly.

SHUTTING DOWN Close the acetylene cylinder valve clockwise all the way.

SHUTTING DOWN Open the torch acetylene valve counterclockwise. Watch both acetylene regulator gauges drop to zero.

SHUTTING DOWN Back out the acetylene regulator adjusting handle counterclockwise until completely loose.

SHUTTING DOWN Close the torch acetylene valve.

SHUTTING DOWN Close the oxygen cylinder valve clockwise all the way.

SHUTTING DOWN Open the torch oxygen valve counterclockwise. Watch both oxygen regulator gauges drop to zero.

SHUTTING DOWN Back out the oxygen regulator adjusting handle counterclockwise until completely loose.

SHUTTING DOWN Close the torch oxygen valve.

SHUTTING DOWN Roll back hoses hang up torch secure oxygen cylinder valve safety cap You can find out more about our welding program at http://weldinglab.mma.edu/