IP Prep Flashcards
Liquid recirculation pump used in an ammonia system is located between
a) compressor and receiver
b) low press receiver and high press receiver
c) low press receiver and evap
d) high press receiver and evap
c
boiling point of r717 ammonia is
a) -28c
b) -27.6c
c) -28f
d) -27f
c
When installing globe valves in any system for component isolation. How should they be installed on horizontal line runs
a) valve stem vertical to line run
b) stem horizontal to line run
c) stem any position so long as high pressure side of system is exerted on seat
d) stem should be at right angles
d
What component is not normally required in cascade systems?
a) condesner
b) receiver
c) refrigerant flow control on secondary coil
d) low stage condenser
b
Which type of intercooler is not suitable for ammonia compression systems?
a) dry type
b) shell and coil
c) open type
d) any above are fine
A
Multi-stage or booster systems used for very low temp are usually required when compression ratios of a single system exceed
a) 20:1
b) 10:1
c) 3:1
d) 5:1
B
Multi stage compression systems can be divided into two major groups which are
a) cascade or extra low
b) cascade or multi stage
c) cascade or direct
d) any above correct
C
An ammonia receiver has the following dimensions 3ft x 60inches long. find correct prv
a) 90cuft/min
b) 90lbs/min
c) 7.5cuft/min
d) 7.5lbs/min
The corrosiveness of a brine and eutectic mixture should maintain between ____ and ___ and can be determined by a ph tester
a) 7 and 6.5
b) 7 and 7.5
c) 7 and 8.5
d) none
d
Normal temp drop through low temp chiller is
a) 2 degC at flow rate of 10-15gal/ton
b) 2degF at flow rate of 10-15gal/ton
c) 10degf at flow rate of 2gal/ton
d) 10degc at flow rate of 2gal/ton
c
Normally ice temperature is controlled by a brine thermostat (return temp). If your saturated
suction temp is 8 degF what should ice temp be?
a) 18deg f
b) 18deg c
c) 28f
d) 28f
b
Centrifugal pumps are widely used, what device can be found in the stuffing box of a pump
a) sleeve bearing
b) ball type bearing
c) mechanical seal
d) packing gland
d
Blank
Blank
When moisture is present in a refrigeration system, it will react with the refrigerant and the oil to form
a) co2
b) acid
c) co
d) all
b
Which of the following represents the lowest vacuum
a) 10psia
b) 5” hg vac
c) 5psig
d) 1000microns
d
A compound gayge
a) indicates pressure above 14.696psia
b) indicates pressures in inches hg below atmospheric
c) is one of two gauges on typical manifold
d) all of the above
d
A micron gauge is used to measure
a) atmospheric pressures at high altitudes
b) atmospheric pressures at sea level
c) absolute pressure below 1mm hg
d) high pressure in refrigeration system
c
Best method of leak checking is when the refrigeration system is
a) in a vacuum
b) open to atmosphere
c) operating with all fans on
d) standing with dry nitrogen pressure as set in b52
d
Non0condensables gases
a) are desirable
b) undesirable
c) condense readily under normal atmospheric conditions
d) help in pulling in a vacuum
b
What Is the most accurate instrument for reading a deep vacuum?
a) compound gauge
b) mercury u tube manometer
c) mercury barometer
d) electronic vacuum gayge
d
To insure accurate testing, best material to use for connecting lines to the vacuum pump and gauge set is
a) light flexible hoses
b) heavy duty rubber gauge line
c) copper tube
d) garden hose
c
Multiple evacuation means that
a) you connect there pumps simultaneously
b) pull a vacuum on 3 diff systems
c) pull vacuum on same system more than once with nitrogen purging between each
c
Moisture in a liquid state must be _____ before it can be removed with a vacuum pump
a) vaporized
b) condensed
c) cooled
d) solidified
a
Which of the following refrigerants is a CFC-type refrigerant
a) r22
b) r-123
c) r-134a
d) r-12
d