Chp4

What are the three items required for combustion to take place?

• fuel, oxygen, flame

• fuel, oxygen, heart source

• fuel, nitrogen, heat source

• gas, carbon monoxide, oxygen

What is meant by stoichiometric combustion?

• It is incomplete combustion

• It is combustion that takes place in every boiler

• It is combustion that requires very little oxygen

• It is the ideal combustion process in which fuel is burned completely

In older boilers, the pilot flame gas pressure is non-adjustable

• True

• False

Which device is not required on a commercial or industrial FM-approved gas train?

• A normally open bleed valve between the safety shutoff valves

• Additional manual shutoff valves

• Two electric safety shutoff valves

• High- and low-gas pressure switches

What is the function of a drip leg used in a gas train?

• It is used to catch oil from the system

• It is used to support the gas train

• It is used as a trap to prevent moisture ad debris from entering the gas valve

• It is used to purge excess air from the gas train

Explain the difference between an atmospheric and power burner

• A power burner is used to force primary air, secondary air, and fuel into the burner tube

• Atmospheric burners introduce primary air through natural means at the inlet, which is mixed with the gas that passes through the manifold spud

• Both A and B are correct

• None of the above

What device creates a narrow constriction at the burner inlet causing the air and gas to be accelerated as they pass through?

• A spud

• A venturi

• An oblique

• A thermopile

What device supervises a standing pilot flame?

• A thermocouple

• A thermopile

• An oblique

• Both A and B are correct

What should the ohm reading be through a hot surface ignition coil?

• Approximately 40 to 90 ohms

• Approximately 50 to 100 ohms

• Approximately 100 to 200 ohms

• Approximately 150 to 250 ohms

Automatic gas valves are typically considered normally open valves

• True

• False