Theory Review

Oxy Fuel and SMAW

Oxy/Fuel

1. What gas provides the hottest flame when burned with oxygen?

a. Natural gasb. Propane

c. Acetylene d. MAPP

• Propane– 4,530 °F (2,500 °C)

• Natural Gas (methane)– 5,190 °F (2,865 °C)

• MAPP - methylacetylene-propadiene propane– 5,300 °F (2,925 °C)

• Acetylene/Oxygen– 5,700 - 6,330 °F (3,150 - 3,500 °C)

2. What flame type has excess oxygen? a. reducing b. neutralc. carburizing d. oxidizing

3. What is the maximum safe working pressure when using acetylene?

a. 15 lbsb. 10 lbs c. 20 lbs d. 30 lbs

DANGER-WARNING

4. Oxygen hoses are a. blue b. green c. red d. red and green striped

5. Devices that prevent the gases from mixing in the hoses are called

a. back stoppersb. one way valves

c. reverse flow check valves d. gas valves

6. The gap created by the cut is called the a. gap b. widthc. kerfd. opening

7. The vertical lines on the face of the cut are called

a. drag linesb. cutting lines c. sever lines d. heat lines

Tip Sizes

8. Oxyfuel torches can cut a. carbon steel b. aluminum c. copper nickel d. all of the above

9. The flames used to bring the metal up to cut- ting temperature are called the

a. warming flames b. cutting flames c. preheat flames d. reducing flames

10. A condition that exists when the flame burns back in the torch is called a

a. burnback b. explosion c. reverse flow d. flashback

SMAW

11. For an E-7018 electrode the 70 stands for the

a. tensile strength times 10,000 lbs b. flux coating c. position the electrode can be used in d. core wire composition

12. The SMAW process uses what type of power supply?

a. constant potential b. constant voltage c. high voltaged. constant current

13. An E-11018 electrodea. is a low hydrogen electrodeb. has a tensile strength of 110,000

PSI c. can be used in all positionsd. is all of the above