Book1: Unit 2 - Review: Chapter 5 - 10 Flashcards
(40 cards)
What is the device used to determine that the fan motor is working:
Select one:
A. Air flow switch
B. Motor contactor
C. Indicator light
D. Power amperage draw meter
E. Flame scanner
A. Air flow switch
The purpose of the gauge glass or water gauge is to show the _____ in the boiler.
Select one:
A. Water level
B. Temperature of the steam
C. Color of the water
D. Steam level
E. Pressure of the water
A. Water level
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. Economizer
D. Boiler feedwater
E. Deaerator
A. Heating system
Each automatically fired hot water boiler shall have a high limit temperature control that will shut off the fuel supply to the boiler to prevent the water from exceeding the maximum allowable temperature of:
Select one:
A. 150°C (302°F)
B. 75°C (167°F)
C. 100°C (212°F)
D. 200°C (392°F)
E. 120°C (248°F)
E. 120°C (248°F)
If the pilot flame fails, no power is generated by the thermocouple preventing the _____ from supplying fuel to the burner on boiler startup.
Select one:
A. Pilot fuel control valve
B. Air supply valve
C. Main fuel control valve
D. Main relay valve
E. Operating control
C. Main fuel control valve
Boiler gauge glasses will break while in service due to the:
Select one:
A. Difference in temperature between the water and steam
B. Strain due to gauge fittings being in line
C. Safety lifting due to over pressure
D. Draft of hot air hitting the glass
E. Thinning of the glass by the action of the steam
E. Thinning of the glass by the action of the steam
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. 25 mm (1 in.) above the bottom of the gauge glass
B. One half of the gauge glass
C. The lowest visible part of the gauge glass
D. The lowest permissible water level
E. 50 mm (2 in.) above the bottom of the gauge glass
C. The lowest visible part of the gauge glass
On a hot water boiler, the highest value on the graduated scale of the pressure gauge shall not be less than _____ times the pressure at which the pressure relief valve is set..
Select one:
A. 3.5
B. 2.5
C. 1.5
D. 2
E. 3
C. 1.5
The blowdown of a safety valve may be decreased by:
Select one:
A. Increasing the spring pressure
B. Raising the lifting lever
C. Decreasing the spring pressure
D. Raising the adjusting ring
E. Lowering the adjusting ring
E. Lowering the adjusting ring
When the main steam stop valves of heating boilers are over 51 mm (2 in.) it is recommended that _____ be used.
Select one:
A. Diaphragm operated valves
B. Solenoid operated valves
C. Globe valves
D. Gate valves
E. OS & Y valves with rising spindles
E. OS & Y valves with rising spindles
A heating boiler must have a permanently attached marker indicating:
Select one:
A. The maximum allowable working temperature
B. Highest permissible water level
C. Lowest permissible steam level
D. The maximum allowable working pressure
E. Lowest permissible water level
E. Lowest permissible water level
The two types of boiler combustion control include:
1. On-Off
2. Automatic
3. Modulating
4. Manual
Select one:
A. 2, 4
B. 3, 4
C. 2, 3
D. 1, 3
E. 1, 2
D. 1, 3
The high gas pressure cut-off switch can be tested by:
Select one:
A. Slowly raising the boiler pressure above the operating setpoint
B. Closing the main gas valve quickly
C. Slowly covering the air supply to the fan
D. Quickly closing the main burner shut-off valve
E. Slowly closing the main gas valve
D. Quickly closing the main burner shut-off valve
A thermocouple consists of two dissimilar wires welded together at one end to form a:
Select one:
A. Cold junction
B. Reference junction
C. Metering junction
D. Hot junction
E. Electric circuit
D. Hot junction
The boiler vent valve is used for the purpose of allowing:
Select one:
A. Air to escape while filling
B. Water to escape while filling
C. Steam to escape while filling
D. Air to escape while draining
E. Steam to enter while draining
A. Air to escape while filling
A flame rod uses the principle that a flame is capable of:
Select one:
A. Heating the rod
B. Conducting electricity
C. Supplying fuel to the burner
D. Holding the solenoid open
E. Holding the solenoid closed
B. Conducting electricity
Before a steam or hot water boiler can be started by a programming control, all but one of the following conditions must be fulfilled:
Select one:
A. The steam pressure or water temperature must be at or below the cut-in setting of the operating control
B. The main power switch or breaker must be closed
C. All manually operated valves in the fuel lines to the pilot and main burner must be closed
D. The water in the boiler drum must be above the cut-off point of the low-water fuel cut-off
E. If the boiler is gas-fired, the fuel supply pressure to the burner valves must be above the cutout point of the low gas pressure cut-off
C. All manually operated valves in the fuel lines to the pilot and main burner must be closed
A programming control on a natural draft gas fires boiler operates in the following sequence.
1. The main burner is ignited
2. The flame detector senses the flame and causes the main gas valve to open
3. The ignition transformer and pilot gas valve are de-energized and closed, if an interrupted pilot is used
4. The operating control initiates a startup
5. The load relay energizes the ignition transformer and the pilot gas valve
Select one:
A. 5, 3, 2, 1, 4
B. 4, 5, 2, 1, 3
C. 2, 5, 1, 4, 3
D. 3, 2, 1, 5, 4
E. 1, 2, 3, 4, 5
B. 4, 5, 2, 1, 3
Purging a furnace means forcing a flow of:
Select one:
A. Air through a furnace for a set period of time when the burner is not in operation.
B. Water through a furnace for a set period of time when the burner is in operation.
C. Fuel through a furnace for a set period of time when the burner is in operation.
D. Fuel through a furnace for a set period of time when the burner is not in operation.
E. Air through a furnace for a set period of time when the burner is in operation.
A. Air through a furnace for a set period of time when the burner is not in operation.
All fitting markings shall be legible and must indicate the following minimum requirements.
1. National Pipe Size
2. Manufacturer’s name or trade mark
3. Vendors Identification
4. Service designation
5. Material designation
Select one:
A. 3, 4, 5
B. 2, 4, 5
C. 1, 3, 5
D. 1, 2, 3
E. 2, 3, 4
B. 2, 4, 5
The flame rod method of sensing is often referred to as:
Select one:
A. Photoelectric scanning
B. Flame rectification
C. Ultraviolet detection
D. Infrared detection
E. The ionized particle principle
B. Flame rectification
A pipe siphon is used on a boiler to:
Select one:
A. Maintain a water seal between the water and the Bourdon tube
B. Maintain a steam seal between the steam and the Bourdon tube
C. Maintain a water seal between the steam and the Bourdon tube
D. Remove water from the boiler drum
E. Add water to the Bourdon tube
C. Maintain a water seal between the steam and the Bourdon tube
Before feedwater enters a boiler the feedwater pipe must be fitted with a:
Select one:
A. Check valve between the stop valve and the boiler
B. Ball valve between the check valve and the boiler
C. Globe valve between the check valve and the boiler
D. Stop valve between the check valve and the boiler
E. Gate valve between the check valve and the boiler
D. Stop valve between the check valve and the boiler
A hydrostatic test is at a pressure of
Select one:
A. 1.5 times atmospheric
B. 1.5 times the maximum allowable working pressure
C. 1.5 times the bursting pressure
D. 1.5 times the operating pressure
B. 1.5 times the maximum allowable working pressure
