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High Pressure Boiler Black Seal Exam Newest 2025/2026 Complete All Questions And Correct Detailed Answers (Verified Answers) |Already Graded A+||Brand New Version!
How are the tube sheets supported in a fire-tube boiler? - ANSWER-by the shell, stays, and tubes
What is the line voltage on the ignition system on a burner? - 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? - ANSWER-to prevent incomplete combustion
What are the two elements in fuel oil that produce most of its heat? - ANSWER-carbon and hydrogen
To eliminate the danger of a furnace explosion during start-up,
the firing sequence must first allow for: - ANSWER-a pre-purge
period
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What is balanced draft? - 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? - ANSWER-Upstream from the safety shut off valve
When the gas limit switch comes into operation, what device does it activate? - ANSWER-fuel line solenoid valve
On a rotary cup type burner, the low gas pressure limit switch
should be electronically interlocked to the: - ANSWER-the fuel
solenoid valve
What must take place in order for combustion air to flow open automatically during equipment operation? - 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: - ANSWER-purging
the furnace after any flame interruption
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What type of draft system is used to overcome resistance on power boilers equipped with an economizer? - ANSWER-an induced draft system
What is the Btu content of natural gas? - ANSWER-100,000 Btu/therm
The term viscosity can best be defined as: - ANSWER-the point
at which oil starts to flow
A gradual increase in the stack temperature could indicate what condition in a boiler? - ANSWER-heating surface fouling
In the ignition system on an oil burner, what causes the spark to jump the gap and ignite the fuel? - ANSWER-a high voltage spark of 10,000V DC produced from the transformer, jumps the gap between the electrode tips.
What are the three types of draft used in power plants? - ANSWER-natural, forced, and induced
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