Oxy-Acetylene Torches

	Extra precaution required for welders. Training / Tool Testing is essential. See Welding Safety doc.

		Eye protection required!

Oxy-Acetylene Torches
The Metal Shop's Oxy-Acetylene Torches
General Info
Make	Various
Model	n/a
Serial	Unknown
Specs	n/a
Manual	n/a
Asylum Info
Location	Metal Shop
Rubric	n/a
Training	Tool classes
Testing	Tool testing, or come to the shop on Tool Testing Night
Restrictions	red

Use for:

• Heating or cutting metal, especially carbon steel.

• Brazing

• Welding (Arc may be preferable)

Do Not Use for

• Anything that might explode when heated.

• Anything that produces excessively noxious gases when heated or burned including:

• Galvanized
• Plated
• Painted
• Oiled
• Powder-coated

Hazards

• Eye damage from looking at the flame for extended periods. Shade 3 eye protection required.

• Poisoning from gases produced when heating or vaporizing certain metals. Respirator required when appropriate.

• Injury or death from explosion due to tool misuse.

• Burns from flame, sparks, or hot workpieces.

• Two highly dangerous situations to watch for. Immediately shut down the torch if either occurs:

1. Pop sound. This is flashback.

2. Purple flame. Burning acetone from tank.

Brief Safety Notes

To avoid serious injury or death, be fully aware of how the tanks, regulators, and torches work in conjunction. Follow safe operating proceedures. For more safety information, see the document:Oxy-Acetylene Safety.

Beware of Flashback: An explosive situation in which Oxygen flows into the Acetylene hose. A pop sound indicates flashback. The equipment has flashback arrestors to keep the flame from backing into the tank. Still, beware.

Never use all the Acetylene in the tank. Tank Acetylene (Short Tank, Red Hose) is mixed with acetone to stabilize it under pressure. If you drain all the Acetylene, acetone will enter the torch to create and explosive situation. Note that Acetone burns purple.

Oxygen under pressure will ignite sawdust and grease. Tank Oxygen (Tall Tank, Green Hose) is under very high pressure. Oil on clothing or hands can combust under pure oxygen.

Avoid standing in front of the regulator especially when opening the cylinder valve. The weakest part of the regulator is the “bonnet,” which tends to be the first to go if the regulator explodes. The adjustment screw will shoot out with the speed of a bullet.

Keep the work area free of flammable or explosive materials especially paper, oil or grease, and flammable solvents such as acetone.

Always store tanks upright never use a tank that has been stored on its side – acetone is heavier than Acetylene and will be released during use and will enter the hose. Acetone burns purple.

If cutting, cut only one sheet at a time. Steel only. No stainless, no high carbon. Consider using a plasma cutter.

Starting Up:

1. Before operation, perform a safety check on the equipment. Was it properly shut down? Were the gas cylinders stored properly?

• Are both cylinders chained up for safety?
• Are both cylinder valves closed?
• Are both regulators screws loose?
• Do all four regulator gauges read zero?
• Are all torch valves closed?
• If the answer is “NO” to any of the above complete the full shut-down procedure below. Be sure to purge the lines. Don’t take shortcuts or skip steps.

2. If needed, connect the torch head appropriate to your operation: Cutting head, welding tip, or heating tip. The shop provides several tip sizes.

3. Set the Acetylene working pressure. (Short Tank, Red Line)

• Open the Acetylene cylinder valve just enough to allow gas to flow. In case of emergency, closing this valve should take an instant.
• Open the Acetylene torch valve about 1/2 a turn.
• Turn the Acetylene regulator screw CLOCKWISE and read the Acetylene regulator gauge to set the pressure. (5 psi is a good beginning pressure.)
• Close the Acetylene torch valve.

NEVER open an Acetylene cylinder valve more than 1.5 turns.

	**Never set the Acetylene pressure higher than 15 psi.** It can explode!

4. Set the Oxygen working pressure. (Tall Tank, Green Line)

• Stand aside from the oxygen regulator. Using two hands, SLOWLY open the Oxygen cylinder valve until the gauge needle stops moving. This reduces the shock of high cylinder pressure on the regulator and reduces the probability of an explosion.
• Turn the oxygen cylinder valve all the way open. The Oxygen cylinder has a seat on the top and bottom that prevents leakage when fully open or fully shut.
• Open the Oxygen torch valve about 1/2 a turn.
• Turn the Oxygen regulator screw CLOCKWISE and use the Oxygen regulator gauge to set the pressure. (5 psi is a good beginning pressure.)
• Close the Oxygen torch valve.

5. Light the torch (Oxygen won’t ignite with a striker, so Acetylene must be lit first.)

• Open the Acetylene torch valve about 1/2 a turn.
• Use a striker to light the Acetylene flame. A gap between the flame and the torch tip indicates too much Acetylene. Use the torch valve to reduce the flow of Acetylene. Adjust as needed.
• SLOWLY open the Oxygen torch valve.
• Adjust the flame using both torch valves as needed to produce a carburizing, neutral, or oxidizing flame.

Shutting Down

	To prevent an explosion, NEVER purge both gases at the same time.

1. Extinguish the torch.

• Close the Oxygen torch valve first.

According to the Victor manual, “Oxygen first” provides users the chance to perform leak checks on both valves every time the torch is shut down. A snap or a pop indicates a leaking oxygen valve, while a small flame at the end of the tip indicates an acetylene gas leak.

• Close the Acetylene torch valve second.

2. Purge the Oxygen lines

• Close the Oxygen cylinder valve. (This cuts the gas off at the source.)
• Open Oxygen torch valve and wait / listen for Oxygen to fully purge from line.
• Check that both Oxygen gauges read zero.
• When the purge is complete and the gauges read zero, turn the Oxygen regulator screw COUNTERCLOCKWISE until slightly loose. Do not remove the screw. If the regulator screw is loosened out of sequence, gas can get trapped in the line between the two regulators.

• Close the Oxygen torch valve. Do not over-tighten.

3. Purge the Acetylene lines.

• Repeat the above steps using the corresponding components.

4. Clean the work area and put equipment away.

• Neatly coil the hoses. Return the equipment rig to its storage location.