Modern Chap. 23 Review questions

Question 1

Which of the following is a function of refrigerant loop components?

a) control refrigerant flow
b) maintain proper refrigerant quantity and quality in the system
c) both A and B
d) Neither A or B

Answer 1

c) both A and B

Question 2

A measurable pressure drop between the evaporator outlet and compressor inlet may indicate that the ________ should be replaced

a) liquid line filter-drier
b) liquid receiver
c) sight glass
d) suction line filter-drier

Answer 2

d) suction line filter-drier

Question 3

Large systems store liquid refrigerant on the high side in the _________

a) liquid line filter-drier
b) liquid receiver
c) sight glass
d) suction line filter-drier

Answer 3

b) liquid receiver

Question 4

The best place to install a sight glass is _______

a) between the metering device and distributor
b) in the discharge line
c) just after the liquid line filter-drier
d) just after the suction line filter-drier

Answer 4

c) just after the liquid line filter-drier

Question 5

A riser valve is a valve installed _______

a) in the compressor discharge line
b) in a length of vertical refrigerant line
c) on the condenser
d) in a liquid line manifold

Answer 5

b) in a length of vertical refrigerant line

Question 6

Which of the following statements regarding service valves is not true?

a) service valves are fastened to tubing using soldered connections
b) service valves provide access for taking pressure readings
c) many systems have a service valve at the outlet of the liquid receiver
d) many service valve stems must be turned using a refrigeration service valve ranch

Answer 6

a) service valves are fastened to tubing using soldered connections

Question 7

A check valve might be used _______

a) to allow refrigerant to bypass one of two metering devices in a heat pump system
b )in multiple-evaporator systems to prevent refrigerant from warmer evaporators from backing up into colder evaporators
c) to prevent unwanted refrigerant migration during the Off cycle of large commercial systems
d) all of the above

Answer 7

all of the above

Question 8

In a multiple evaporator system, a check valve is installed at the _______

a) compressor inlet
b) condenser inlet
c) outlet of the warmest evaporator
d) outlet of the coldest evaporator

Answer 8

d) outlet of the coldest evaporator

Question 9

A solenoid valve that opens a small valve that directs pressure to open and close a larger valve is ________

a) direct-acting
b) normally closed
c) pilot-operated
d) all of the above

Answer 9

c) pilot-operated

Question 10

Ice accumulation on an evaporator can be quickly melted by automatically opening a system’s ________

a) hot gas defrost
b) liquid receiver
c) manifold valve
d) moisture indicator

Answer 10

a) hot gas defrost

Question 11

A ________ valve alleviates low pressure and temperature conditions by diverting some refrigerant vapour from the compressor discharge directly to the low side

a) desuperheater
b) hot-gas bypass
c) relief
d) riser

Answer 11

b) hot-gas bypass

Question 12

A hot-gas bypass valve directs hot-gas refrigerant from the discharge line to the ________

a) condenser
b) liquid line
c) liquid receiver
d) low side of the system

Answer 12

d) low side of the system

Question 13

The purpose of a crankcase pressure regulator is to _________

a) ensure that compressor discharge pressure is sufficiently high
b) increase liquid line pressure in low-ambient conditions
c) maintain a sufficiently low pressure in the compressor
d) show the flow of liquid refrigerant

Answer 13

c) maintain a sufficiently low pressure in the compressor

Question 14

A commercial refrigeration system with a single suction line and multiple evaporators can maintain a different temperature at each evaporator by controlling and differing

a) crankcase pressure
b) evaporator pressure
c) head pressure
d) liquid line temperature

Answer 14

b) evaporator pressure

Question 15

The purpose of an evaporator pressure regulator is to ______

a) bypass liquid line refrigerant around the metering device
b) control evaporator temp by controlling its pressure
c) isolate parts of the system for service
d) shut off the compressor if evaporator pressure gets too high

Answer 15

b) control evaporator temperature by controlling its pressure

Question 16

Which of the following relief valves is designed to vent refrigerant under excessive pressure and then close when the system pressure has been lowered

a) fusible plug
b) manifold valve
c) rupture disc
d) spring-loaded relief valve

Answer 16

d) spring-loaded relief valve

Question 17

Which of the following statements regarding relief valves is NOT true?

a) a blown fusible plug must be replaced
b) relief valves should be replace every 5 years
c) relief valves should be vented outdoors using a purge line
d) spring loaded relief valves should be stacked to prevent any leakage

Answer 17

d) spring loaded relief valves should be stacked to prevent any leakage

Question 18

A device that opens when condenser pressure rises to a proper level and closes to block the flow of refrigerant from the condenser to the liquid receiver when condenser pressure drops too low is a ________

a) condenser pressure regulator
b) crankcase pressure regulator
c) receiver pressure regulator
d) split condenser valve

Answer 18

a) condenser pressure regulator

Question 19

A device that allows hot refrigerant vapour from the compressor discharge line to bypass the condenser and directly enter the liquid receiver when a certain pressure difference occurs between the discharge line and the liquid receiver is a

a) condenser pressure regulator
b) crankcase pressure regulator
c) receiver pressure regulator

Answer 19

c) receiver pressure regulator

Question 20

A method of head pressure control in low-ambient conditions in which a condenser is divided into two separate spaces (one space flooded, the other isolated) is called _________

a) combined flow
b) condenser splitting
c) counterflow
d) drift

Answer 20

b) condenser splitting