DC BOILER EXAM ACTUAL EXAM 2024 NEWEST
COMPLETE 250 QUESTIONS AND CORRECT DETAILED
ANSWERS (100% VERIFIED ANSWERS) |ALREADY
GRADED A+|| BRAND NEW!!
The component in which liquid vapor by absorbing heat is called? - ANSWER:
Evaporator
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
During a 24 hours operation how often should you check the water level? - ANSWER:
Once per shift
, A 15 psi steam boiler produces 8000 pound of steam per hour. The
Minimum pipe size for the pipe leaving the boiler is___12__inches.
(Density is 0.037 lbs/ft3)
Equation: - ANSWER: D = 12 (C/d/h /.7854)
D = 12 (.037/60) = 3,603.60
D = .ft = 3,927
D = 3.603.,927 = 0.917647058
D = 0.957938963 * 12
D = 11.49 OR 12 "pipe
The boiler steam line is 350 Feet long. During start-up the pipe is heated
From 60 F to 350 F. The 350 F. The pipe wills expand__7.92__inches
Due to the change in temperature
Equation: - ANSWER: (T 1 - T2) x L x .0000065
(350 - 60) x 350 x .0000065
290 x 350 x 12 x .0000065 = 7.92
A 12" pipe filled with water to a height of 250 feet will have a pressure of
_________at the bottom of the pipe?
Equation:
P = FT / 2.31 - ANSWER: 250 feet / 2.31 = 108.22
A "5" pipe filled with water to a height of 75 feet will have a pressure of
_________at
The bottom of the pipe?
Equation:
P = FT / 2.31 - ANSWER: 75 feet / 2.31 = 32.46
What is the flow rate, in gallons per minute, of water flowing through a 8' pipe
At a velocity of 7 feet per second? - ANSWER: GPM = V X D²
0.4085
GPM = 7 x (8 x 8)
0.4085
GPM = 448
0.4085
GPM = 1096.69 gpm
What is the flow rate, in gallons per minute, of water flowing through a 4' pipe At a
velocity of 12 feet per second? - ANSWER: GPM = V X D²
0.4085
GPM = 12 x (4 x 4)
0.4085
COMPLETE 250 QUESTIONS AND CORRECT DETAILED
ANSWERS (100% VERIFIED ANSWERS) |ALREADY
GRADED A+|| BRAND NEW!!
The component in which liquid vapor by absorbing heat is called? - ANSWER:
Evaporator
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
During a 24 hours operation how often should you check the water level? - ANSWER:
Once per shift
, A 15 psi steam boiler produces 8000 pound of steam per hour. The
Minimum pipe size for the pipe leaving the boiler is___12__inches.
(Density is 0.037 lbs/ft3)
Equation: - ANSWER: D = 12 (C/d/h /.7854)
D = 12 (.037/60) = 3,603.60
D = .ft = 3,927
D = 3.603.,927 = 0.917647058
D = 0.957938963 * 12
D = 11.49 OR 12 "pipe
The boiler steam line is 350 Feet long. During start-up the pipe is heated
From 60 F to 350 F. The 350 F. The pipe wills expand__7.92__inches
Due to the change in temperature
Equation: - ANSWER: (T 1 - T2) x L x .0000065
(350 - 60) x 350 x .0000065
290 x 350 x 12 x .0000065 = 7.92
A 12" pipe filled with water to a height of 250 feet will have a pressure of
_________at the bottom of the pipe?
Equation:
P = FT / 2.31 - ANSWER: 250 feet / 2.31 = 108.22
A "5" pipe filled with water to a height of 75 feet will have a pressure of
_________at
The bottom of the pipe?
Equation:
P = FT / 2.31 - ANSWER: 75 feet / 2.31 = 32.46
What is the flow rate, in gallons per minute, of water flowing through a 8' pipe
At a velocity of 7 feet per second? - ANSWER: GPM = V X D²
0.4085
GPM = 7 x (8 x 8)
0.4085
GPM = 448
0.4085
GPM = 1096.69 gpm
What is the flow rate, in gallons per minute, of water flowing through a 4' pipe At a
velocity of 12 feet per second? - ANSWER: GPM = V X D²
0.4085
GPM = 12 x (4 x 4)
0.4085
