Actual Exam Questions and Correct
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How are the tube sheets supported in a fire-tube boiler? ---------CORRECT
ANSWER-----------------by the shell, stays, and tubes
What is the line voltage on the ignition system on a burner? ---------CORRECT
ANSWER-----------------the line voltage could vary but is typically 120 V AC.
When making adjustments to the firing rate of a power boiler, why should the air
be increased to the burner before the fuel? ---------CORRECT ANSWER-----------------
to prevent incomplete combustion
What are the two elements in fuel oil that produce most of its heat? ---------
CORRECT ANSWER-----------------carbon and hydrogen
To eliminate the danger of a furnace explosion during start-up, the firing
sequence must first allow for: ---------CORRECT ANSWER-----------------a pre-purge
period
,What is balanced draft? ---------CORRECT ANSWER-----------------the forced draft
and induced draft fans are regulated to keep the furnace below atmospheric
pressure
When installing a boiler, where must the filter and strainers for oil fired boilers be
installed? ---------CORRECT ANSWER-----------------Upstream from the safety shut
off valve
When the gas limit switch comes into operation, what device does it activate? -----
----CORRECT ANSWER-----------------fuel line solenoid valve
On a rotary cup type burner, the low gas pressure limit switch should be
electronically interlocked to the: ---------CORRECT ANSWER-----------------the fuel
solenoid valve
What must take place in order for combustion air to flow open automatically
during equipment operation? ---------CORRECT ANSWER-----------------There must
be an adequate opening for the flow of fuel gas into the confines of the boiler
room to ensure proper combustion
, Furnace explosions can best be avoided by: ---------CORRECT ANSWER-----------------
purging the furnace after any flame interruption
What type of draft system is used to overcome resistance on power boilers
equipped with an economizer? ---------CORRECT ANSWER-----------------an induced
draft system
What is the Btu content of natural gas? ---------CORRECT ANSWER-----------------
100,000 Btu/therm
The term viscosity can best be defined as: ---------CORRECT ANSWER-----------------
the point at which oil starts to flow
A gradual increase in the stack temperature could indicate what condition in a
boiler? ---------CORRECT ANSWER-----------------heating surface fouling
In the ignition system on an oil burner, what causes the spark to jump the gap and
ignite the fuel? ---------CORRECT ANSWER-----------------a high voltage spark of
10,000V DC produced from the transformer, jumps the gap between the
electrode tips.