1. Question: What is the primary purpose of a safety valve on a boiler?
o A) To increase boiler efficiency
o B) To maintain water level
o C) To relieve excess pressure
o D) To feed water into the boiler
ANSWER : C
Explanation: A safety valve prevents overpressure conditions by
automatically releasing steam when pressure exceeds safe limits.
2. Question: What type of fuel is typically used in a stationary boiler?
o A) Diesel only
o B) Coal, oil, or gas
o C) Only natural gas
o D) Biomass only
ANSWER : B
Explanation: Stationary boilers can burn various fuels, including
coal, oil, or gas, depending on design and application.
3. Question: The purpose of a boiler’s blowdown valve is to:
o A) Drain excess water to control water level
o B) Remove sediment and impurities
o C) Feed more water into the boiler
o D) Release steam pressure
ANSWER : B
Explanation: Blowdown valves remove sludge and scale from the
, bottom of the boiler, maintaining water quality and preventing
damage.
4. Question: Which type of boiler is commonly used for low-pressure
heating systems?
o A) Fire-tube boiler
o B) Water-tube boiler
o C) Flash boiler
o D) Supercritical boiler
ANSWER : A
Explanation: Fire-tube boilers are simple, reliable, and commonly
used for low-pressure applications.
5. Question: What is the purpose of a boiler economizer?
o A) To increase water pressure
o B) To preheat feedwater using exhaust gases
o C) To reduce fuel consumption by lowering steam temperature
o D) To store excess steam
ANSWER : B
Explanation: Economizers capture residual heat from flue gases to
preheat feedwater, improving efficiency.
6. Question: Which of the following indicates water level in a boiler?
o A) Pressure gauge
o B) Thermometer
o C) Sight glass
o D) Draft gauge
ANSWER : C
Explanation: Sight glasses allow visual monitoring of the water
level inside the boiler.
7. Question: What is priming in a boiler?
o A) Water boiling at lower pressure
o B) Carryover of water droplets with steam
o C) Cleaning the boiler tubes
, o D) Initial startup of the fuel supply
ANSWER : B
Explanation: Priming is the carryover of water with steam, often
due to high water levels or sudden load changes.
8. Question: What is foaming in a boiler?
o A) Formation of bubbles in feedwater
o B) Excessive steam pressure
o C) Incomplete combustion of fuel
o D) Rust formation inside boiler
ANSWER : A
Explanation: Foaming is caused by impurities in water, producing
bubbles that can lead to priming.
9. Question: A water-tube boiler differs from a fire-tube boiler in that:
o A) Water flows inside the tubes, and hot gases flow outside
o B) Hot gases flow inside tubes, water outside
o C) Water and steam are in separate vessels
o D) It does not require a safety valve
ANSWER : A
Explanation: In water-tube boilers, water circulates inside tubes
while hot gases surround them, allowing high-pressure operation.
10.Question: What is the function of a superheater?
o A) Increase water pressure
o B) Convert water into steam
o C) Increase steam temperature above saturation
o D) Reduce fuel consumption
ANSWER : C
Explanation: Superheaters raise the temperature of steam beyond
the boiling point, improving efficiency and turbine performance.
11.Question: What is the recommended blowdown frequency for a low-
pressure boiler?
o A) Once a week
, o B) Daily
o C) Every hour
o D) Only during shutdown
ANSWER : B
Explanation: Frequent blowdown prevents sediment buildup and
maintains water quality.
12.Question: What is the typical maximum pressure for a third-class
stationary boiler?
o A) 15 psi
o B) 50 psi
o C) 100 psi
o D) 250 psi
ANSWER : B
Explanation: Third-class boilers are generally rated for pressures
not exceeding 50 psi for safety and operational purposes.
13.Question: What is the function of a boiler feedwater pump?
o A) Remove steam from the system
o B) Circulate water through the economizer
o C) Supply water to the boiler under pressure
o D) Reduce boiler pressure
ANSWER : C
Explanation: Feedwater pumps supply water into the boiler,
overcoming internal pressure to maintain water levels.
14.Question: Which component prevents backflow from a boiler?
o A) Pressure relief valve
o B) Check valve
o C) Blowdown valve
o D) Steam trap
ANSWER : B
Explanation: Check valves allow flow in one direction, preventing
water or steam from flowing backward.
o A) To increase boiler efficiency
o B) To maintain water level
o C) To relieve excess pressure
o D) To feed water into the boiler
ANSWER : C
Explanation: A safety valve prevents overpressure conditions by
automatically releasing steam when pressure exceeds safe limits.
2. Question: What type of fuel is typically used in a stationary boiler?
o A) Diesel only
o B) Coal, oil, or gas
o C) Only natural gas
o D) Biomass only
ANSWER : B
Explanation: Stationary boilers can burn various fuels, including
coal, oil, or gas, depending on design and application.
3. Question: The purpose of a boiler’s blowdown valve is to:
o A) Drain excess water to control water level
o B) Remove sediment and impurities
o C) Feed more water into the boiler
o D) Release steam pressure
ANSWER : B
Explanation: Blowdown valves remove sludge and scale from the
, bottom of the boiler, maintaining water quality and preventing
damage.
4. Question: Which type of boiler is commonly used for low-pressure
heating systems?
o A) Fire-tube boiler
o B) Water-tube boiler
o C) Flash boiler
o D) Supercritical boiler
ANSWER : A
Explanation: Fire-tube boilers are simple, reliable, and commonly
used for low-pressure applications.
5. Question: What is the purpose of a boiler economizer?
o A) To increase water pressure
o B) To preheat feedwater using exhaust gases
o C) To reduce fuel consumption by lowering steam temperature
o D) To store excess steam
ANSWER : B
Explanation: Economizers capture residual heat from flue gases to
preheat feedwater, improving efficiency.
6. Question: Which of the following indicates water level in a boiler?
o A) Pressure gauge
o B) Thermometer
o C) Sight glass
o D) Draft gauge
ANSWER : C
Explanation: Sight glasses allow visual monitoring of the water
level inside the boiler.
7. Question: What is priming in a boiler?
o A) Water boiling at lower pressure
o B) Carryover of water droplets with steam
o C) Cleaning the boiler tubes
, o D) Initial startup of the fuel supply
ANSWER : B
Explanation: Priming is the carryover of water with steam, often
due to high water levels or sudden load changes.
8. Question: What is foaming in a boiler?
o A) Formation of bubbles in feedwater
o B) Excessive steam pressure
o C) Incomplete combustion of fuel
o D) Rust formation inside boiler
ANSWER : A
Explanation: Foaming is caused by impurities in water, producing
bubbles that can lead to priming.
9. Question: A water-tube boiler differs from a fire-tube boiler in that:
o A) Water flows inside the tubes, and hot gases flow outside
o B) Hot gases flow inside tubes, water outside
o C) Water and steam are in separate vessels
o D) It does not require a safety valve
ANSWER : A
Explanation: In water-tube boilers, water circulates inside tubes
while hot gases surround them, allowing high-pressure operation.
10.Question: What is the function of a superheater?
o A) Increase water pressure
o B) Convert water into steam
o C) Increase steam temperature above saturation
o D) Reduce fuel consumption
ANSWER : C
Explanation: Superheaters raise the temperature of steam beyond
the boiling point, improving efficiency and turbine performance.
11.Question: What is the recommended blowdown frequency for a low-
pressure boiler?
o A) Once a week
, o B) Daily
o C) Every hour
o D) Only during shutdown
ANSWER : B
Explanation: Frequent blowdown prevents sediment buildup and
maintains water quality.
12.Question: What is the typical maximum pressure for a third-class
stationary boiler?
o A) 15 psi
o B) 50 psi
o C) 100 psi
o D) 250 psi
ANSWER : B
Explanation: Third-class boilers are generally rated for pressures
not exceeding 50 psi for safety and operational purposes.
13.Question: What is the function of a boiler feedwater pump?
o A) Remove steam from the system
o B) Circulate water through the economizer
o C) Supply water to the boiler under pressure
o D) Reduce boiler pressure
ANSWER : C
Explanation: Feedwater pumps supply water into the boiler,
overcoming internal pressure to maintain water levels.
14.Question: Which component prevents backflow from a boiler?
o A) Pressure relief valve
o B) Check valve
o C) Blowdown valve
o D) Steam trap
ANSWER : B
Explanation: Check valves allow flow in one direction, preventing
water or steam from flowing backward.
