Chapter 5 Flashcards
Special diverter fittings are required in blank to ensure an adequate flow of water through each convector.
A. one-pipe hot water systems.
B. loop systems.
C. two-pipe reverse return systems.
D. multi-zone systems.
A
With the pump running in a hot water heating system, the normal differential pressure between the suction and discharge is blank.
A. 2 kPa, [4 psi]
B. 55 kPa, [8 psi]
C. 75 kPa, [12 psi]
D. 10 kPa, [1.5 psi]
B
Which of the following should be included in the routine operation of a hot water heating system?
A. Testing the controls and the safety relief valve on a regular basis.
B. Keeping the boiler room and boiler clean and tidy.
C. Refer periodically to the boiler manufacturer’s operation instructions.
D. All of the above.
D
If there is an air lock after repairs have been made on a piping system, the operator should
a. Increase speed of the pump to force out the air
b. Add chemicals to absorb the trapped air
c. Open the system vent valves or check operation of the automatic air vending system
d. Increase the temperature of the system to boil out the trapped air
C
in smaller hot water heating systems, inline circulating pumps are:
a)Metering
b)High pressure pumps
c)Low head pumps
d)Rotary vane pumps
c
Air dissolved in the hot water heating system water is likely to be liberated in:
a)The high point in the system because cold water holds less air
b)The expansion tank
c)The point of no pressure change where the air comes out of solution
d)The boiler because heated water holds less air
d
To reduce the normal operating pressure range of a hot water heating system you must adjust:
a)The water level in expansion tank
b)The make up water PRV
c)The temperature controller
d)The water level in the boiler
b
Flow control valves are installed in each zone of a multi-zone pumped hot water heating system to:
a)Ensure the expansion tank does not flood
b)Ensure the system is balanced
c)Prevent continued circulation of hot water after the circulator stops
d)Ensure adequate hot water supply to each zone
c
When hot water heating systems are initially filled, they are brought to a minimum pressure of
a)12 psi/83 psi
b)15 psi/103 kPa
c)30 psi/206 kPa
d)8 psi/55 kPa
a
Improper location of the circulating pump in a hot water heating system can lead to
a)The point of no return
b)Overpressure
c)The point of no pressure change
d)Cavitation
d
A circulating pump in a hot water heating system is commonly a _____________ pump.
a)Turbine
b)Positive displacement
c)Multistage
d)Single stage
d
The point of no pressure change in a hot water heating system depends on the location of:
a)The air vents
b)The boiler
c)The circulator
d)The expansion tank
d
Air enters a hot water heating system with:
a)Pumped return
b)Chemical reaction with water treatment agents
c)Make-up water
d)The expansion tank
c
When the boiler and circulating pump in a large hot water heating system are located on the top floor of the building, care must be taken to ensure_________________.
a)Sufficient total head for the pump
b)Sufficient suction lift for the pump
c)Elevator access to the mechanical room
d)Sufficient suction head for the pump
d
