Topics: All categories in the pool
1: R-22 is considered a(n)
- HFC
- HCFCH
- CFC
- HCFC
2: At higher altitudes, the boiling point of refrigerant is
- equal to the coefficient of water at 32F
- the same
- lower
- higher
3: R-410A is classified as a ____ refrigerant on the safety matrix.
- A-1
- B-2
- B-1
- A-2
4: Viscosity is
- the coefficient of external friction
- a measure of heat content
- the ability of oil to flow
- measure of weight
5: The actual expansion curve of compression follows most nearly which one of the following curves?
- Pressure Temperature
- Isothermal
- Volume Temperature
- Adiabatic
6: Evaporators located ____inches of a heating coil shall be equipped whit a pressure relief device.
- 10
- 18
- 15
- 24
7: How is bring measured?
- hydrometer
- manometer
- anemometer
- hygrometer
8: Horizontal piping should be run level.
- False
- Yes, if the condenser is located above the evaporator
- No, unless the supervisor on the job says so.
- True
9: Which of the following most closely represents the concentration of Li-Br in a absorption system?
- 40% Li-Br, 60% tap water
- 50% Li-Br, 50% tap water
- 40% Li-Br, 60% distilled water
- 60% Li-Br, 40% distilled water
10: Low pressure chiller systems use what type of compressor?
- Scroll
- Centrifugal
- Reciprocating
- Screw
11: Aluminum, Zinc, Magnesium, or their alloys shall not be used in contact with
- trichlorotrifluoromethane
- ammonia
- methyl chloride
- R-718
12: Can ammonia be used on domestic system?
- yes
- no
- no, unless there is proper ventilation system installed
- yes, for systems under 10 tons
13: By using nitrogen within a pipe during brazing operation,
- The explosion hazard is confined
- Exterior scale formation is minimized
- Discoloration is prevented
- Copper oxide formation is prevented
14: A chiller entering and leaving temperature difference is?
- 20 degrees F
- 50 degrees F
- 10 degrees F
- 5 degrees F
15: How many opening forces operate a thermostatic expansion valve?
- 2
- 4
- 1
- 3
16: Pressure vessels with an internal volume of 3 cubic feet or less
- shall use pressure relief devices or fusible plugs
- shall use pressure relief devices
- do not need pressure relief protection
- shall use fusible plugs
17: Adjusting the spring pressure on a TXV
- makes no difference
- changes subcooling
- adjusts the bulb charge
- changes superheat
18: A solder joint melts at temperatures of
- less than 400F
- 600F to 900F
- 1,200F to 1,500F
- 400F to 800F
19: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.
- high pressure
- low pressure
- critical pressure
- design pressure
20: Pressure vessels with an internal volume of 10 cubic feet or more
- shall use pressure relief devices or fusible plugs
- shall use pressure relief devices
- shall use rupture discs or duel pressure relief valves
- shall use fusible plugs
21: What is the state of the refrigerant leaving the evaporator?
- a low temperature subcooled liquid
- a high temperature superheated vapor
- a high temperature subcooled liquid
- low temperature superheated vapor
22: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
- 55 lbs
- 500 lbs
- 660 lbs
- 330 lbs
23: In a horizontal shell & tube condenser, the ammonia is liquefied by
- removing the latent heat of vaporization
- water sprayed over condenser
- removing the latent heat of fusion
- passing thru the tubes from top to bottom
24: Can you use Ammonia in industrial applications?
- Yes, always
- Yes, Under certain condidtions
- No, never
- When mixed with R-718
25: What section of ASHRAE-15 governs pressure vessels?
- Section 6 ASHRAE-34 ASME VIII unfired
- Section 7 ASHRAE-15 ASME VIII fired
- OSHA
- Section 9 ASHRAE-15 ASME VIII unfired