DC THIRD CLASS STATIONARY BOILERS 323
EXAM 2026 MASTER PREPARATION MANUAL
◉ Select the best answer electrical grounding method? Answer:
Metal stake drive 8 foot into the ground.
◉ A _____ valve should be used for throttling purpose? 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? 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: Back wash
Backwash, brine, rinse, service
◉ Where is medium temperature is 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
◉ What type of safety valve is this? Answer: ( Full) Crosby nozzle-
type safety valve. Page 365 BOG
◉ Where do you found superheat reading? 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? Answer: Grounding Electrode
Conductor
,◉ Where do 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. Page 403 BOG
◉ 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. 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? 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
EXAM 2026 MASTER PREPARATION MANUAL
◉ Select the best answer electrical grounding method? Answer:
Metal stake drive 8 foot into the ground.
◉ A _____ valve should be used for throttling purpose? 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? 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: Back wash
Backwash, brine, rinse, service
◉ Where is medium temperature is 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
◉ What type of safety valve is this? Answer: ( Full) Crosby nozzle-
type safety valve. Page 365 BOG
◉ Where do you found superheat reading? 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? Answer: Grounding Electrode
Conductor
,◉ Where do 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. Page 403 BOG
◉ 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. 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? 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
