Book 1: 2-07 - Low Water Fuel Cut-Offs & Feedwater Controls Flashcards
The low water level fuel cut-off will shut off the fuel to the heating boiler when the water level drops below:
Select one:
A. 50 mm (2 in.) above the bottom of the gauge glass
B. The lowest permissible water level
C. 25 mm (1 in.) above the bottom of the gauge glass
D. The lowest visible part of the gauge glass
E. One half of the gauge glass
D. The lowest visible part of the gauge glass
Low water fuel cut-off devices require regular attention, the following intervals are recommended:
1. Once per shift
2. Daily
3. Weekly
4. Monthly
5. No attention is required
Select one:
A. 3, 4, 5
B. 1, 2, 3
C. 1, 2, 4
D. 2, 3, 4
E. 2, 3, 5
D. 2, 3, 4
In a building heating system the condensate in the condensate receiver tank comes from the:
Select one:
A. Heating system
B. Make-up water supply
C. Deaerator
D. Economizer
E. Boiler feedwater
A. Heating system
Possible causes of low water level include:
1. Leaks caused by breakage or corrosion
2. Excessive blowdown
3. Automatic feedwater valve passing
4. Boiler feed pump failure
5.Excessive make-up
Select one:
A. 3, 4, 5
B. 1, 2, 4
C. 2, 3, 5
D. 2, 3, 4
E. 1, 2, 3
B. 1, 2, 4
The low water fuel cut-off float is commonly used to operate both the Low water fuel cut-off switch and the:
Select one:
A. Low fuel gas pressure switch
B. Low steam pressure alarm
C. Low feedwater temperature alarm
D. High steam pressure switch
E. Feedwater control switch
E. Feedwater control switch
A second source of feedwater may be controlled by the:
Select one:
A. Boiler drum level control
B. Boiler operating control
C. Automatic blowdown device
D. Low water fuel cut-off device
E. Feedwater control switch
D. Low water fuel cut-off device
At normal boiler steaming rates, a condensate receiver tank should contain a sufficient volume of water equivalent to the water evaporated by the boiler for a maximum period of _____ minutes.
Select one:
A. 30
B. 15
C. 20
D. 45
E. 60
A. 30
Make-up water for the heating system usually comes from the:
Select one:
A. City water supply
B. Returning condensate
C. Boiler feedwater
D. Boiler feedwater pump
E. Deaerator
A. City water supply
The float in the low water fuel cut-off will activate:
Select one:
A. A globe valve
B. A gate valve
C. A solenoid valve
D. An electrical relay
E. An electrical switch
E. An electrical switch
The float operated low water fuel cut-off works on the principle of:
Select one:
A. Temperature change
B. Steam density
C. Drum level variation
D. Buoyancy
E. Differential pressure
D. Buoyancy
At normal boiler steaming rates, a condensate receiver tank should contain a sufficient volume of water equivalent to the water evaporated by the boiler for a maximum period of _____ minutes.
Select one:
A. 45
B. 60
C. 20
D. 30
E. 15
D. 30
Make-up water for the heating system usually comes from the:
Select one:
A. Returning condensate
B. Deaerator
C. Boiler feed water
D. City water supply
E. Boiler feed water pump
D. City water supply
In a building heating system the condensate in the condensate receiver tank comes from the:
Select one:
A. Make-up water supply
B. Heating system
C. Deaerator
D. Boiler feed water
E. Economizer
B. Heating system
Low water fuel cut-off devices require regular attention, the following intervals are recommended:
1. Once per shift
2. Daily
3. Weekly
4. Monthly
5. No attention is required
Select one:
A. 3,4,5
B. 1,2,4
C. 2,3,5
D. 2,3,4
E. 1,2,3
D. 2,3,4
The main cause of heating boiler failure is overheating of the heating surfaces due to:
Select one:
A. High water conditions
B. High firing rates
C. Low steak conditions
D. Low water conditions
E. Scale build-up
D. Low water conditions
