DC 3rd Class Test, 3rd class
stationary steam engineer
license prep, Stationary
Engineer, Station engineer
exam, DC 1st Class Boiler
Exam Study Guide – Practice
Questions with Verified
Answers. GRADED A+. Latest
2026/2027 Update
The component in which liquid vapor by absorbing heat is called? -
Answer✔✔-evaporator
the best answer for an electrical grounding method? - Answer✔✔-Metal stake
drive 8 foot into the ground.
A _____ valve should be used for throttling purposes? - Answer✔✔-Globe
,What is the acceptable range for residual sodium sulfite in the boiler maintain?
- Answer✔✔-30-70
What is the BTU content of a gallon of #4 fuel oil? - Answer✔✔-146,000
What does a zeolite water softener system use as a means of regeneration? -
Answer✔✔-brine
What are the 4 steps for a Zeolite Rejuvenation water softener process? -
Answer✔✔-Backwash, Brine, Rinse, Service
Where medium temperature liquid found? - Answer✔✔-Condenser
Where is high temperature vapor found? - Answer✔✔-At the discharge of the
compressor or condenser
What stays are used to support the burner chamber in a scotch marine boiler? -
Answer✔✔-Diagonal Stays
What type of safety valve is this? - Answer✔✔-( Full) Crosby nozzle-type safety
valve. Page 365 BOG
Where do you get superheat reading? - Answer✔✔-Take suction line pressure
Name the wire that connects all component of a system to a physical ground or
water pipe? - Answer✔✔-Grounding electrode conductor
,Where do you get sub-cooling reading? - Answer✔✔-Take liquid line pressure
Cross reference to temperature using a P/T Chart
Get liquid line temperature
Subtract actual temperature from cross referenced temperature
Result is Sub cooling
On the boilers that have both Quick opening and Screw type blow down valves,
the Quick opening valve must be located? - Answer✔✔-closest to the boiler
and followed by the screw-type valve
High pressure boilers equipped with Quick opening and Screw type valves are
blown down how? - Answer✔✔-By opening the Quick opening valve first and
closing it Last.
ASME Code defines a slow opening valve as what? - Answer✔✔-One requiring
at least 5 full 360 degree turns between full open and close position.
A 300 Horsepower boiler operating at 100psi has an average load of 75% with
80% condensate return and 5% blow down. The treatment provides a chemical
which costs $8.75 per gallon, and will treat 600 gallon. Find the amount of the
chemical needed for the day period, and the cost of the chemical for a 30 days
period? - Answer✔✔-Water In = Water Out
Makeup + Condensate Return = Evaporator + Blow Down
Average Evaporator Rate = 300 x 34.5 pph x .75% load = 7762, 50 pph
, 1 Month + .8( 7762.50 pph) = 7762.50 pph + 0500 m
1 Month + 6210 pph = 7762.50 pph + .0500 m
-6210 -6210
1 Month = 1552.5 pph + .0500
.9500 m = 1552.5 pph
.9500m .9500
1Month = 1,634.21 pph
Gallons per Month = 1634..33 x 24 x 30 = 141, 252.24 gallons per month
Chemical needed = 141,252.24 gallon / 600 gallon = 235, 40 gallon
Cost per month = 235, 40 gallon x 8.75 = $2,059.75
During a 24 hours operation how often should you check the water level? -
Answer✔✔-once per shift
How often do you check the high limit switch? - Answer✔✔-Annually
What is the recommended time for a complete external inspection of a boiler?
- Answer✔✔-once per shift
What is the first thing to do when shutting down a boiler? - Answer✔✔-To turn
off the fire
stationary steam engineer
license prep, Stationary
Engineer, Station engineer
exam, DC 1st Class Boiler
Exam Study Guide – Practice
Questions with Verified
Answers. GRADED A+. Latest
2026/2027 Update
The component in which liquid vapor by absorbing heat is called? -
Answer✔✔-evaporator
the best answer for an electrical grounding method? - Answer✔✔-Metal stake
drive 8 foot into the ground.
A _____ valve should be used for throttling purposes? - Answer✔✔-Globe
,What is the acceptable range for residual sodium sulfite in the boiler maintain?
- Answer✔✔-30-70
What is the BTU content of a gallon of #4 fuel oil? - Answer✔✔-146,000
What does a zeolite water softener system use as a means of regeneration? -
Answer✔✔-brine
What are the 4 steps for a Zeolite Rejuvenation water softener process? -
Answer✔✔-Backwash, Brine, Rinse, Service
Where medium temperature liquid found? - Answer✔✔-Condenser
Where is high temperature vapor found? - Answer✔✔-At the discharge of the
compressor or condenser
What stays are used to support the burner chamber in a scotch marine boiler? -
Answer✔✔-Diagonal Stays
What type of safety valve is this? - Answer✔✔-( Full) Crosby nozzle-type safety
valve. Page 365 BOG
Where do you get superheat reading? - Answer✔✔-Take suction line pressure
Name the wire that connects all component of a system to a physical ground or
water pipe? - Answer✔✔-Grounding electrode conductor
,Where do you get sub-cooling reading? - Answer✔✔-Take liquid line pressure
Cross reference to temperature using a P/T Chart
Get liquid line temperature
Subtract actual temperature from cross referenced temperature
Result is Sub cooling
On the boilers that have both Quick opening and Screw type blow down valves,
the Quick opening valve must be located? - Answer✔✔-closest to the boiler
and followed by the screw-type valve
High pressure boilers equipped with Quick opening and Screw type valves are
blown down how? - Answer✔✔-By opening the Quick opening valve first and
closing it Last.
ASME Code defines a slow opening valve as what? - Answer✔✔-One requiring
at least 5 full 360 degree turns between full open and close position.
A 300 Horsepower boiler operating at 100psi has an average load of 75% with
80% condensate return and 5% blow down. The treatment provides a chemical
which costs $8.75 per gallon, and will treat 600 gallon. Find the amount of the
chemical needed for the day period, and the cost of the chemical for a 30 days
period? - Answer✔✔-Water In = Water Out
Makeup + Condensate Return = Evaporator + Blow Down
Average Evaporator Rate = 300 x 34.5 pph x .75% load = 7762, 50 pph
, 1 Month + .8( 7762.50 pph) = 7762.50 pph + 0500 m
1 Month + 6210 pph = 7762.50 pph + .0500 m
-6210 -6210
1 Month = 1552.5 pph + .0500
.9500 m = 1552.5 pph
.9500m .9500
1Month = 1,634.21 pph
Gallons per Month = 1634..33 x 24 x 30 = 141, 252.24 gallons per month
Chemical needed = 141,252.24 gallon / 600 gallon = 235, 40 gallon
Cost per month = 235, 40 gallon x 8.75 = $2,059.75
During a 24 hours operation how often should you check the water level? -
Answer✔✔-once per shift
How often do you check the high limit switch? - Answer✔✔-Annually
What is the recommended time for a complete external inspection of a boiler?
- Answer✔✔-once per shift
What is the first thing to do when shutting down a boiler? - Answer✔✔-To turn
off the fire
