HVAC 6017 - Hot Water Heating System Equipment and Operation (Chp 5) Flashcards
An air pocket in a hot water heating system will cause:
A) Insufficient heat in parts of the system
B) Noise in the system
C) All of these answers are correct
D) Total or partial blockage of water flow to some parts of the system
E) Insufficient water circulation
C) All of these answers are correct
Firing a hot water boiler after refilling with water will result in:
A) Change of state B) Scaling C) Overheating D) Release of air into the system E) Chemical destabilization
D) Release of air into the system
The expansion tank in a hot water heating system is normally attached to the:
A) Boiler or the hot water supply line near the boiler
B) Supply line after the circulating pump
C) Highest point in the system directly above the boiler
D) Return line directly before the boiler
E) Supply line above the lowest convector
A) Boiler or the hot water supply line near the boiler
To prevent hot water heating system damage:
A) The boiler should be blown down frequently after start up
B) A drain valve should be temporarily installed before the boiler
C) The expansion valve should be drained several times
D) A temporary strainer should be installed before the circulating water pump
E) The vents should be opened wide frequently
D) A temporary strainer should be installed before the circulating water pump
Typical construction contaminants sometimes encountered in a ''new hot water system are'': A) All of the above B) Pipe dope C) Welding slag, soldering flux D) Thread cuttings, thread cutting oils E) Dirt
A) All of the above
After a steam heating system has been operating for some time, you notice that some sections of the system are still cold. Which one of the following could be the cause of this?
A) Steam does not contain enough heat
B) Boiler water pressure too low
C) Air is trapped in the affected sections
D) Boiler water temperature too low
E) Condensate temperature too low
C) Air is trapped in the affected sections
Diverter fittings are used in one pipe system in the supply lines to heating units when:
A) A higher heating output is required from the heating unit
B) To compensate for a low heating load
C) There are no balancing valves installed in the supply line
D) The distance from the boiler to heating unit is short
E) A hydraulic balance must be corrected
A) A ‘‘higher heating output’’ is required from the heating unit
The highest point of a heating system above the boiler is 19.8 m. The pressure gauge on the boiler should indicate at least: A) 255 kPa B) 25 psi C) 46 psi D) 216 kPa E) 206 kPa
E) 206 kPa
A new hot water system must be cleaned before start up to:
A) Keep the boiler inspector satisfied B) Prevent the water from becoming acidic and corrosive C) Prevent air infiltration D) Keep the water clean E) Fulfil the contractor’s obligation
B) Prevent the water from becoming acidic and corrosive
To regulate the flow of hot water to a zone circuit a:
A) Balancing valve is used B) Gate valve is used C) Flow control valve is used D) Pressure reducing valve is used E) Diverter fitting is used
A) Balancing valve is used
NOTE: regulate the flow of hot water to a zone circuit
The correct quantity for each chemical used to clean a heating boiler includes:
- 1kg/420 L of trisodiumphosphate
- 2 L/340 L of 18% muriatic acid
- 1kg/420 L of caustic soda
- 1kg/250 L of soda ash
A) 1, 3, 4 B) 1, 2, 3 C) 2, 3, 4 D) 1, 2, 4 E) 1, 2, 3, 4
A) 1, 3, 4 NOTE: 1. 1kg/420 L of trisodiumphosphate 3. 1kg/420 L of caustic soda 4. 1kg/250 L of soda ash
An air separator should always be installed in a/an:
A) Converter B) Cross tee C) Horizontal pipe D) Expansion tank E) Vertical pipe
C) Horizontal pipe
What type of air vent uses dics that readily absorb water and expand?
A) Airtrol B) Manual Petcock C) Float Operated D) Handwheel E) Hygroscopic
E) Hygroscopic
