AY Honors/Welding/Answer Key

(Instructor Required)

The Welding Honor is perhaps of all the AY honors, the one with the greatest potential to cause injury. Do not attempt to teach yourself how to weld. An experienced instructor is absolutely required for this honor.

1. Identify all parts of the following:

a. Welding and cutting torches

A welding torch has a nozzle with one hole, the torch body mixes oxy and acet, and you get your flame.

A cutting torch has a bunch of nozzles in a circle, with an oxy/acet mix (like the welding torch), and a bigger hole in the middle where oxygen comes out.

The outer holes heat the steel, the inner hole cuts.

c. Oxygen and acetylene hoses and their differences

Oxygen hoses are green. Acetylene hoses are red.

HOSES: The oxy acetylene welding hoses are made out of a durable rubber that is designed to withstand different pressures. There are several things to remember about the hoses:

• Red = Fuel • Green = Oxygen • Do not kink hoses • Keep hoses away from work area • Wrap hoses when not in use • Keep hoses away from sparks and hot metal

d. Oxygen and acetylene tanks and their differences

The oxygen and acetylene cylinders are designed to hold high-pressure gases. There are some important things to remember when using these cylinders:

• Cylinders must always be stood upright and be secured by a chain • When not in use (regulator mounted) they must always have a valve protection cap in place • Cylinders should be stored in a cool dry place away from direct sunlight or extreme cold

Oxygen Cylinders

• Usually red in colour, smaller in diameter and taller than Acetylene • 2200 PSI when full • The cylinder valve must be opened fully (double seated valve) or it could leak! • You should not run an oxygen tank below 50 PSI.

Acetylene Cylinders

• Usually black, large in diameter and short • 250 PSI when full • The cylinder valve should only be opened ¼ of a turn. • The acetylene cylinder should never be laid down as this will result in the gas becoming unstable. • You should not run an acetylene tank below 50 PSI.

2. Explain the safe working pressures of oxygen and acetylene, as per your instruc­tor's directions, for various procedures.

When welding and brazing with an oxy-acetylene torch, acetylene should be set at 5psi. Oxygen should be set at 5 or 6psi, but no more.

When cutting with an oxy-acetylene torch, acetylene should again be set at about 5psi. Oxygen, however is set much higher, about 25psi, when cutting.

1. Always use goggles when welding or cutting

2. Use aprons and gloves.

3. Do not point the flame towards the regulators and another person.

4. When finished welding shut off the main valves , bleed the lines and loosen the regulator adjusting screws.

5. Wind up the hoses when finished shutting everything off.

6. Do not turn acetylene valve more than 1 ½ turns.

7. Never use oil near oxygen equipment

8. Threads used for acetylene are LEFT-HANDED.

9. Threads used for oxygen are RIGHT HANDED.

10. There will be no horseplay.

8. Explain the difference between oxyacetylene and electric arc welding.

Oxy-acetylene welding uses two gases in the process of producing a weld. Acetylene, which is the fuel and is the main source of heat, and oxygen, which is a propellant.

Electric arc welding does not use gas to produce a weld like oxy-acetylene welding does. Electric arc welding uses an electric current to produce its welds. A clamp, with the one side of the current flowing through it, is attached to a base plate. Then the another clamp/nozzle, with the other side of the current flowing through it, is held in a hand. A filler rod is then used to complete the circuit and create the heat needed to heat the pieces of metal being joined and melt the filler rod (used to bind the pieces of metal together).

References

• Steelworker, Volume 1, A U.S. Navy Training Manual. As an original document produced by the U.S. government, this publication is in the public domain and has a lot of information that should be incorporated into this text.