1 | Page
DC THIRD TESTING 2025 UPDATED
ACTUAL EXAM WITH CORRECT
SOLUTIONS.
The component in which liquid vapor by absorbing heat is
called? - correct answer- Evaporator
Select the best answer electrical grounding method? - correct
answer- Metal stake drive 8 foot into the ground.
A _____ valve should be used for throttling purpose? - correct
answer- Globe
What is the acceptable range for residual sodium sulfite in the
boiler maintain? - correct answer- 30-70
What is the BTU content of a gallon of #4? - correct answer-
146,000
What does a zeolite water softener system use as a means of
regeneration? - correct answer- Brine
,2 | Page
What are the 4 steps for a Zeolite Rejuvenation water softener
process? - correct answer- Back wash
Backwash, brine, rinse, service
Where is medium temperature is liquid found? - correct answer-
Condenser
Where is high temperature vapor found? - correct answer- At
the discharge of the compressor or condenser
What stays are used to support the burner chamber in a scotch
marine boiler? - correct answer- Diagonal Stays
What type of safety valve is this? - correct answer- ( Full)
Crosby nozzle-type safety valve. Page 365 BOG
What type of safety valve is this? - correct answer- ( Full)
Crosby nozzle-type safety valve. Page 365 BOG
,3 | Page
Where do you found superheat reading? - correct answer- Take
suction line pressure
Cross reference using a P/T Chart
Get tail coil Temperature
Subtract cross references temperature from tail coil
temperature
Result will be superheat
Name the wire that connects all component of a system to a
physical ground or water pipe? - correct answer- Grounding
Electrode Conductor
Where do get sub-cooling reading? - correct 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? -
correct answer- Closest to the boiler and followed by the screw
type valve
, 4 | Page
High pressure boilers equipped with Quick opening and Screw
type valves are blown down how? - correct answer- By opening
the Quick opening valve first and closing it Last. Page 403 BOG
ASME Code defines a slow opening valve as what? - correct
answer- One requiring at least 5 full 360 degree turns between
full open and close position. Page 374
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? - correct 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
DC THIRD TESTING 2025 UPDATED
ACTUAL EXAM WITH CORRECT
SOLUTIONS.
The component in which liquid vapor by absorbing heat is
called? - correct answer- Evaporator
Select the best answer electrical grounding method? - correct
answer- Metal stake drive 8 foot into the ground.
A _____ valve should be used for throttling purpose? - correct
answer- Globe
What is the acceptable range for residual sodium sulfite in the
boiler maintain? - correct answer- 30-70
What is the BTU content of a gallon of #4? - correct answer-
146,000
What does a zeolite water softener system use as a means of
regeneration? - correct answer- Brine
,2 | Page
What are the 4 steps for a Zeolite Rejuvenation water softener
process? - correct answer- Back wash
Backwash, brine, rinse, service
Where is medium temperature is liquid found? - correct answer-
Condenser
Where is high temperature vapor found? - correct answer- At
the discharge of the compressor or condenser
What stays are used to support the burner chamber in a scotch
marine boiler? - correct answer- Diagonal Stays
What type of safety valve is this? - correct answer- ( Full)
Crosby nozzle-type safety valve. Page 365 BOG
What type of safety valve is this? - correct answer- ( Full)
Crosby nozzle-type safety valve. Page 365 BOG
,3 | Page
Where do you found superheat reading? - correct answer- Take
suction line pressure
Cross reference using a P/T Chart
Get tail coil Temperature
Subtract cross references temperature from tail coil
temperature
Result will be superheat
Name the wire that connects all component of a system to a
physical ground or water pipe? - correct answer- Grounding
Electrode Conductor
Where do get sub-cooling reading? - correct 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? -
correct answer- Closest to the boiler and followed by the screw
type valve
, 4 | Page
High pressure boilers equipped with Quick opening and Screw
type valves are blown down how? - correct answer- By opening
the Quick opening valve first and closing it Last. Page 403 BOG
ASME Code defines a slow opening valve as what? - correct
answer- One requiring at least 5 full 360 degree turns between
full open and close position. Page 374
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? - correct 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
