Modern Chap 10 - Review questions

Question 1

The _______ sets refrigerant cylinder regulations.

a) occupational safety and health administration (OSHA)
b) Environmental protection agency (EPA)
c) Department of transportation (DOT)
d) Department of Labour (DOL)

Answer 1

c) department of transportation (DOT)

Question 2

Large refrigerant cylinders are protected against bursting by a _________

a) protective cap
b) compressible bladder at bottom of the tank
c) small surge tank
d) fusible plug

Answer 2

d) fusible plug

Question 3

Large refrigerant cylinders called ______ cylinders are often positioned upside-down with their valves at the bottom.

a) recovery
b) storage
c) disposable
d) returnable

Answer 3

b) storage

Question 4

The operating element used in pressure gauges that is made of a thin-walled tube of metal bent into a circular shape is called a _____.

a) bourdon tube
b) thermocouple
c) bimetal strip
d) retarder

Answer 4

a) bourdon tube

Question 5

A pressure gauge that is specifically designed to measure lower-than-atmospheric pressure is a ____.

a) compound gauge
b) vacuum pump
c) high-pressure gauge
d) vacuum gauge

Answer 5

d) vacuum gauge

Question 6

A pressure gauge designed to measure pressure above and below atmospheric pressure is a ___.

a) vacuum gauge
b) compound gauge

Answer 6

b) compound gauge

Question 7

A pressure gauge that can read high-pressure values on a single continuous scale, usually from 0 to 800 psi, is a ___.

a) vacuum gauge
b) compound gauge
c) high-pressure gauge
d) recovery gauge

Answer 7

c) high pressure gauge

Question 8

A service port is closed off from the refrigeration system when the service valve is ___.

a) backseated
b) front seated
c) mid position

Answer 8

a) back seated

Question 9

Which of the following service valves is located on the low side of the refrigeration system?

a) discharge service valve
b) suction service valve
c) king valve
d) queen valve

Answer 9

b) suction service valve

Question 10

Mostly used for checking pressure, a(n) ___ does not have a service valve to control the flow of refrigerant.

a) queen valve
b) king valve
c) access port
d) valve core remover

Answer 10

access port

Question 11

The device that engages an extra spring in a pressure gauge to adjust the gauge’s calibration to higher graduation marks on its scale is a ___.

a) bourdon tube
b) thermocouple
c) bimetal strip
d) retarder

Answer 11

d) retarder

Question 12

during normal system operation, hot high pressure refrigerant vapour flows through the _______ service valve

a) discharge
b) liquid line
c) suction line

Answer 12

b) liquid line

Question 13

An externally threaded valve with a spring-loaded center pin is called a ___.

a) discharge service valve
b) piercing valve
c) Schrader valve
d) king valve

Answer 13

c) Schrader valve

Question 14

A technician must use a ____ to access small hermetic systems that do not have service valves or access ports.

a) valve core remover
b) king valve
c) schrader valve
d) pricing valve

Answer 14

d) piercing valve

Question 15

The process of removing unwanted air, vapors, dirt, or moisture from gauge manifold hoses by venting them to the atmosphere is called ___.

a) purging
b) evacuating
c) recovering
d) reclaiming

Answer 15

a) purging

Question 16

Areas where leaks are likely to occur include all of the following except ____.

a) tubing connections
b) straight runs of tubing
c) high vibration areas
d) brazed joints

Answer 16

b) straight runs of tubing

Question 17

Which system procedure is normally done with both hand valves opened on a gauge manifold connected to a refrigeration system?

a) brazing
b) evacuation
c) liquid charging
d) pressure readings

Answer 17

b) evacuation

Question 18

The leak detection method involving the application of soap and water solution to areas where leaks are ___ methods

a) refrigerant dye
b) halide torch
c) ultrasonic
d) bubble solution

Answer 18

d) bubble solution

Question 19

The leak detection method that uses an ultraviolet light to find leaking refrigerant is ___ method.

a) fluorescent dye
b) halide torch
c) electronic detector
d) bubble solution

Answer 19

a) fluorescent dye

Question 20

The leak detection method that involves burning a fuel gas near a copper plate and using a rubber hose to siphon air near leaking refrigerant is ___ method

a) fluorescent dye
b) halide torch
c) refrigerant dye
d) ultrasonic detector

Answer 20

b) halide torch

Question 21

Which of the following is a disadvantage of using an electronic leak detector?

a) cannot detect small leaks
b) can only be used with one refrigerant type
c) hard to see leaks in bright areas
d) produces false alarms near urethane insulation

Answer 21

d) produces false alarms

Question 22

The leak detection method that detects the sound vapor escaping is ____ method

a) fluorescent dye
b) halide torch
c) ultrasonic detector

Answer 22

c) ultrasonic detector

Question 23

A device used for creating vacuums to dehydrate a system is a ____.

a) vacuum gauge
b) bourdon tube
c) retarder
d) vacuum pump

Answer 23

d) vacuum pump

Question 24

Which of the following terms is used to specify the speed at which gas can be pumped through a vacuum pump?

a) blank off pressure
b) ultimate vacuum
c) free air displacement
d) single-stage volume

Answer 24

c) free air displacement

Question 25

Which type of vacuum pump is capable of pulling the deepest vacuum?

Answer 25

two-stage vacuum pump (high vacuum method)

Question 26

Cleaning a refrigerant for reuse by oil separation and single or multiple passes through a filter-drier defines ___ a refrigerant.

a) reclaiming
b) recovering
c) recycling
d) evacuating

Answer 26

c) recycling

Question 27

Removing a refrigerant from a system and storing it in a external container, regardless of the condition of the refrigerant, defines ____ a refrigerant

a) reclaiming
b) recovering
c) recycling
d) evacuating

Answer 27

b) recovering

Question 28

Reprocessing a refrigerant so that it is chemically pure defines _____ a refrigerant.

a) reclaiming
b) recovering
c) recycling
d) evacuating

Answer 28

a) reclaiming

Question 29

The weight of the refrigerant cylinder when it is empty is referred to as it’s ____ weight.

Answer 29

Tare

Question 30

An instrument used to monitor the weight of a refrigerant cylinder as refrigerant is being charged into or recovered from a system is a ____________

Answer 30

digital charging scale

Question 31

List the three main types of pressure gauges used in HVACR

Answer 31

1. compound gauge
2. high-pressure gauge
3. vacuum gauge

Question 32

List three things that a technician can do to maintain service valves and extend their service life;

Answer 32

1. Always clean and oil a valve stem
2. Apply turning force gradually
3. tighten plug/cap firmly

Question 33

What will happen if dirty oil is left in a vacuum pump?

Answer 33

will reduce the pumps ultimate vacuum

Question 34

which service valve position helps prevent damage to gauges when pressures are being measured during system operation? Explain why

Answer 34

The cracked-open position acts as a throttle to help prevent high-pressure surges from damaging gauges when measuring system pressure.

Question 35

Explain why an oily or dusty area on refrigeration equipment would indicate a possible leak?

Answer 35

When there is a system leak, a small amount of oil may escapealong with the refrigerant.Dust often gathers and sticks to oily areas

Question 36

What will happen if dirty oil is left in a vacuum pump?

Answer 36

Sludge will form, reducing the service life of the pump. Dirty oil also reduces a pump’s ultimate vacuum capability