DC 3rd Class Test
1. The component in which liquid vapor by absorbing heat is called <Ans>
evapo- rator
2. the best answer for an electrical grounding method <Ans> Metal stake drive
8 foot into the ground.
3. A valve should be used for throttling purposes <Ans> Globe
4. What is the acceptable range for residual sodium sulfite in the boiler main-
tain <Ans> 30-70
5. What is the BTU content of a gallon of #4 fuel oil <Ans> 146,000
6. What does a zeolite water softener system use as a means of regeneration?-
: brine
7. What are the 4 steps for a Zeolite Rejuvenation water softener process
<Ans> -
Backwash, Brine, Rinse, Service
8. Where medium temperature liquid found <Ans> Condenser
9. Where is high temperature vapor found <Ans> At the discharge of the
compressor or condenser
10. What stays are used to support the burner chamber in a scotch marine
,boiler <Ans> Diagonal Stays
11. What type of safety valve is this <Ans> ( Full) Crosby nozzle-type safety valve
Page 365 BOG
12. Where do you get superheat reading <Ans> Take suction line pressure
13. Name the wire that connects all component of a system to a physical
ground or water pipe <Ans> Grounding electrode conductor
14. Where do you get sub-cooling reading <Ans> 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
15. On the boilers that have both Quick opening and Screw type blow down
valves, the Quick opening valve must be located <Ans> closest to the boiler
and followed by the screw-type valve
16. High pressure boilers equipped with Quick opening and Screw type valves
are blown down how <Ans> By opening the Quick opening valve first and closing
it Last.
17. ASME Code defines a slow opening valve as what <Ans> One requiring
at least 5 full 360 degree turns between full open and close position.
,18. 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 <Ans> 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
19. During a 24 hours operation how often should you check the water level?-
: once per shift
20. How often do you check the high limit switch <Ans> Annually
21. What is the recommended time for a complete external inspection of a
1. The component in which liquid vapor by absorbing heat is called <Ans>
evapo- rator
2. the best answer for an electrical grounding method <Ans> Metal stake drive
8 foot into the ground.
3. A valve should be used for throttling purposes <Ans> Globe
4. What is the acceptable range for residual sodium sulfite in the boiler main-
tain <Ans> 30-70
5. What is the BTU content of a gallon of #4 fuel oil <Ans> 146,000
6. What does a zeolite water softener system use as a means of regeneration?-
: brine
7. What are the 4 steps for a Zeolite Rejuvenation water softener process
<Ans> -
Backwash, Brine, Rinse, Service
8. Where medium temperature liquid found <Ans> Condenser
9. Where is high temperature vapor found <Ans> At the discharge of the
compressor or condenser
10. What stays are used to support the burner chamber in a scotch marine
,boiler <Ans> Diagonal Stays
11. What type of safety valve is this <Ans> ( Full) Crosby nozzle-type safety valve
Page 365 BOG
12. Where do you get superheat reading <Ans> Take suction line pressure
13. Name the wire that connects all component of a system to a physical
ground or water pipe <Ans> Grounding electrode conductor
14. Where do you get sub-cooling reading <Ans> 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
15. On the boilers that have both Quick opening and Screw type blow down
valves, the Quick opening valve must be located <Ans> closest to the boiler
and followed by the screw-type valve
16. High pressure boilers equipped with Quick opening and Screw type valves
are blown down how <Ans> By opening the Quick opening valve first and closing
it Last.
17. ASME Code defines a slow opening valve as what <Ans> One requiring
at least 5 full 360 degree turns between full open and close position.
,18. 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 <Ans> 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
19. During a 24 hours operation how often should you check the water level?-
: once per shift
20. How often do you check the high limit switch <Ans> Annually
21. What is the recommended time for a complete external inspection of a
