DC 3rd Class Test questions with verified detailed solutions
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
The component in which liquid vapor by absorbing heat is called?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
evaporator
the best answer for an electrical grounding method?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Metal stake drive 8 foot into the ground. ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
A _____ valve should be used for throttling purposes?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Globe
What is the acceptable range for residual sodium sulfite in the boiler maintain?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
30-70
What is the BTU content of a gallon of #4 fuel oil? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
146,000
What does a zeolite water softener system use as a means of regeneration?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
brine
What are the 4 steps for a Zeolite Rejuvenation water softener process?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Backwash, Brine, Rinse, Service ||\\//|| ||\\//|| ||\\//||
Where medium temperature liquid found? ||\\//|| ||\\//|| ||\\//|| ||\\//||
Condenser
Where is high temperature vapor found? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
At the discharge of the compressor or condenser
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
What stays are used to support the burner chamber in a scotch marine boiler?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Diagonal Stays ||\\//||
What type of safety valve is this? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
( Full) Crosby nozzle-type safety valve. Page 365 BOG
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Where do you get superheat reading? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
,Take suction line pressure ||\\//|| ||\\//|| ||\\//||
Name the wire that connects all component of a system to a physical ground or water pipe? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Grounding electrode conductor ||\\//|| ||\\//||
Where do you get sub-cooling reading? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
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? ||\\//|| ||\\//|| ||\\//|| ||\\//||
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?
By opening the Quick opening valve first and closing it Last.
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
ASME Code defines a slow opening valve as what? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
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? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
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?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
once per shift ||\\//|| ||\\//||
How often do you check the high limit switch?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Annually
What is the recommended time for a complete external inspection of a boiler?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
once per shift ||\\//|| ||\\//||
What is the first thing to do when shutting down a boiler?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
To turn off the fire
||\\//|| ||\\//|| ||\\//|| ||\\//||
A flow control should be blown down when?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
once per shift ||\\//|| ||\\//||
How often should you check the Low Water Fuel Cut off?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
once per shift ||\\//|| ||\\//||
Why is oil added to the refrigerant?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
lubrication of the compressor ||\\//|| ||\\//|| ||\\//||
Keep refrigerant migrating ||\\//|| ||\\//||
Recycled and filtered refrigerant can be used where? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
By the same owner in the same type of equipment
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Data printed on the equipment nameplate would include manufacturer, model, and serial
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
number and________________? ||\\//||
Stamp of approval from commissioning authority ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
The component in which liquid vapor by absorbing heat is called?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
evaporator
the best answer for an electrical grounding method?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Metal stake drive 8 foot into the ground. ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
A _____ valve should be used for throttling purposes?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Globe
What is the acceptable range for residual sodium sulfite in the boiler maintain?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
30-70
What is the BTU content of a gallon of #4 fuel oil? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
146,000
What does a zeolite water softener system use as a means of regeneration?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
brine
What are the 4 steps for a Zeolite Rejuvenation water softener process?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Backwash, Brine, Rinse, Service ||\\//|| ||\\//|| ||\\//||
Where medium temperature liquid found? ||\\//|| ||\\//|| ||\\//|| ||\\//||
Condenser
Where is high temperature vapor found? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
At the discharge of the compressor or condenser
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
What stays are used to support the burner chamber in a scotch marine boiler?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Diagonal Stays ||\\//||
What type of safety valve is this? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
( Full) Crosby nozzle-type safety valve. Page 365 BOG
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Where do you get superheat reading? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
,Take suction line pressure ||\\//|| ||\\//|| ||\\//||
Name the wire that connects all component of a system to a physical ground or water pipe? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Grounding electrode conductor ||\\//|| ||\\//||
Where do you get sub-cooling reading? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
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? ||\\//|| ||\\//|| ||\\//|| ||\\//||
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?
By opening the Quick opening valve first and closing it Last.
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
ASME Code defines a slow opening valve as what? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
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? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
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?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
once per shift ||\\//|| ||\\//||
How often do you check the high limit switch?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Annually
What is the recommended time for a complete external inspection of a boiler?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
once per shift ||\\//|| ||\\//||
What is the first thing to do when shutting down a boiler?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
To turn off the fire
||\\//|| ||\\//|| ||\\//|| ||\\//||
A flow control should be blown down when?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
once per shift ||\\//|| ||\\//||
How often should you check the Low Water Fuel Cut off?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
once per shift ||\\//|| ||\\//||
Why is oil added to the refrigerant?
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
lubrication of the compressor ||\\//|| ||\\//|| ||\\//||
Keep refrigerant migrating ||\\//|| ||\\//||
Recycled and filtered refrigerant can be used where? ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
By the same owner in the same type of equipment
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
Data printed on the equipment nameplate would include manufacturer, model, and serial
||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
number and________________? ||\\//||
Stamp of approval from commissioning authority ||\\//|| ||\\//|| ||\\//|| ||\\//|| ||\\//||
