Book 2: 5-25 - "Compression Refrigeration System Pre-Startup Procedures" Flashcards
Just before charging an empty refrigerating system, the entire system should be:
Select one:
A. Hydro tested
B. Pressure tested
C. Boiled out
D. Pressures to the maximum allowable working pressure
E. Put under a very high vacuum
E. Put under a very high vacuum
Non-condensable gases in a refrigeration system consist mainly of _____ that may have leaked into the system by improper operating or maintenance procedures.
Select one:
A. Gases caused by lubrication breakdown
B. Sulphur dioxide
C. Air
D. Impurities in the refrigerant
E. Nitrogen oxide
C. Air
Evacuation of the refrigeration system should not be attempted unless the temperature of the surrounding air is _____ or higher.
Select one:
A. 0°C (32°F)
B. 10°C (50°F)
C. 20°C (68°F)
D. 15°C (59°F)
E. 5°C (41°F)
C. 20°C (68°F)
Once any leaks found in the system are repaired:
Select one:
A. Refrigerant can be added to the system
B. The system should be evacuated
C. The system is ready for operation
D. The pressure can be released
E. A second pressure test should be conducted
E. A second pressure test should be conducted
The initial refrigerant charge is given on the _____ side of the system.
Select one:
A. Expansion valve outlet
B. Low-pressure
C. Compressor inlet
D. Evaporator
E. High-pressure
E. High-pressure
As the pressurizing gas is admitted to the refrigeration system the pressure is first increased to the required:
Select one:
A. High-pressure side maximum design pressure
B. High-pressure side minimum design pressure
C. Low-pressure side minimum design pressure
D. High-pressure side operating pressure
E. Low-pressure side operating pressure
C. Low-pressure side minimum design pressure
Frost formation on the suction line in a _____ system may indicate overcharging.
Select one:
A. Automatic expansion
B. High-pressure float
C. Capillary tube
D. Thermostatic expansion
E. Low-pressure float
C. Capillary tube
It is the _____ part of the refrigerant molecular composition that during combustion causes the green flame of the halide detector.
Select one:
A. Hydrogen
B. Chlorine
C. Carbon
D. Fluorine
E. Iodine
B. Chlorine
Caution when burned the halocarbon refrigerants containing fluorine produce a very toxic _____ gas.
Select one:
A. Sulphur dioxide
B. Mustard
C. Hydrogen sulphide
D. Phosgene
E. Carbon monoxide
D. Phosgene
What personal protective equipment (PPE) is required when charging a system with refrigerant?
Select one:
A. Face shield
B. Goggles
C. Rubber gloves
D. Encapsulated suit
E. Self contained breathing apparatus
B. Goggles
Purge systems are required on refrigeration systems that operate:
Select one:
A. Above atmospheric temperature
B. Only with ammonia as the refrigerant
C. Below atmospheric pressure
D. Without a qualified operator in attendance
E. Below atmospheric temperature
C. Below atmospheric pressure
The pressurizing gas is admitted to the refrigeration system through the _____ valve.
Select one:
A. Charging
B. King
C. Queen
D. Isolation
E. Drain
A. Charging
If any moisture or water vapour is present in a refrigerating system that contains chlorine or fluorine an acid is formed that reacts with the compressor oil to produce sludge that will:
Select one:
A. Corrode metal parts
B. Plug the expansion valve
C. Restrict cooling water flow
D. Clog the condenser
E. Coat the evaporator
A. Corrode metal parts
An alternate method to leak testing with a soap solution when using nitrogen is the:
Select one:
A. X-ray radiography
B. Infrared scanner
C. Magnetic flux tester
D. Ultraviolet scanner
E. Ultrasonic detector
E. Ultrasonic detector
The refrigeration system condenser pressure should be slightly higher than the saturation pressure corresponding to the temperature of the refrigerant in the:
Select one:
A. Upstream side of the compressor
B. Accumulator
C. Evaporator
D. Condenser
E. Downstream side of the expansion valve
D. Condenser