Chapter 14 (REFRIGERATION)

Question 1

Which of the following could be used to check a leak in ammonia system?

Answer 1

Litmus Paper
Sulfur Stick

Question 2

Ammonia leaks in the condenser can be detected by

Answer 2

Applying litmus paper to the circulating water discharge

Question 3

A sulfur stick burning in the presence of ammonia will give off a

Answer 3

dense white smoke

Question 4

An ammonia leak will turn litmus paper

Answer 4

blue

Question 5

In an ammonia system the oil gauge must be kept:

Answer 5

closed except when checking oil level

Question 6

Valves and piping 8n ammonia system are made of:

Answer 6

iron

Question 7

The relief valve in an ammonia machine is located:

Answer 7

in the compressor head

Question 8

When purging an ammonia condenser into a bucket of water, one can tell when the air is out and ammonia starts to come through by the:

Answer 8

change of bubbling sound of air to the crackling sound of ammonia

Question 9

The crossover connection in an ammonia system can be used to

Answer 9

hot gas defrost

Question 10

How is an ammonia system purged so that operator will not be overcome by the fumes?

Answer 10

into a bucket of water

Question 11

Thermal expansion valves are usually of the:

Answer 11

diaphragm
bellows type

Question 12

When checking zinc plates in a condenser, one should:

Answer 12

clean the plates snd renew worn out ones

Question 13

The scale trap is located between the:

Answer 13

king (liquid) valve snd expansion valve

Question 14

When the evaporator coils are located in the icebox, the system is known as

Answer 14

direct system

Question 15

The purge valve is located:

Answer 15

in the highest part of the system

Question 16

The solenoid valve is:

Answer 16

a temperature controlled stop valve

Question 17

The thermal expansion valve is located between the:

Answer 17

solenoid valve and the evaporator coils

Question 18

The purpose of scale trap is to:

Answer 18

remove dirt, scale and metal chips from the refrigerant

Question 19

The oil separator (trap) is located between the:

Answer 19

compressor discharge valve and the condenser

Question 20

The charging connection in a refrigerating system is located:

Answer 20

between the king valve and the solenoid valve

Question 21

The dehydrator is located between the

Answer 21

receiver and the expansion valve

Question 22

The charging valve is located between the

Answer 22

king valve and the expansion valve

Question 23

The solenoid valve is located between the

Answer 23

scale trap and the thermal expansion valve

Question 24

A device used to keep moisture from passing through the system is called

Answer 24

dehydrator

Question 25

The relief valve is located on the

Answer 25

discharge side of the compressor

Question 26

The dehydrator is used:

Answer 26

to remove moisture from the system when adding refrigerant to the system

Question 27

Which of the following is another name for liquid valve?

Answer 27

king valve

Question 28

If no gaskets are used in the piping joints of a Freon system, the joints must be:

Answer 28

ground joints

Question 29

A device for holding open the suction valve snd drawing gas from the suction manifold snd returning it to the suction line without compressing it is called

Answer 29

cylinder unloader

Question 30

The solenoid valve can be typed as

Answer 30

magnetic stop valve

Question 31

The bulb for thermal expansion valve is located

Answer 31

near the evaporator coil outlet

Question 32

The elements of a thermostat switch are usually of the

Answer 32

bimetal type

Question 33

The expansion valve is located between the

Answer 33

receiver snd evaporator

Question 34

The oil separator is located between the

Answer 34

compressor and condenser

Question 35

Zinc rods are found in the

Answer 35

salt water side of condenser

Question 36

A double trunk piston is used to

Answer 36

all of the above

Question 37

Which of the following gasket materials should be used on a Freon system?

Answer 37

Asbestos Metallic

Question 38

Many pressure gauges on a Freon System have two dials or graduations on one gauge. The two dials represent

Answer 38

pressure and temperature

Question 39

A double type condenser has

Answer 39

a small pipe inside s larger pipe, the cooling water passing through the small pipe and the refrigerant through the large pipe

Question 40

When there is a freon leak, the halide torch will burn

Answer 40

green

Question 41

Large leaks in a Freon system cannot always be detected with a halide torch because ir changer color with the slightest amount of freon present. A large leak can be detected easier by applying

Answer 41

a soapsuds solution, mixed with a little glycerin at to hold the solution together, and watch for bubbles

Question 42

The relief valve on a CO2 machine is located

Answer 42

on the discharge pipe between the compressor and the discharge valve

Question 43

The discharge pressure of the compressor should be

Answer 43

the pressure which corresponds to a temperature from 5°F to 15°F higher than the condenser discharge

Question 44

The purpose if relief valves on regrigeration machines is to:

Answer 44

prevent excessive pressure in case of stoppage on the discharge side of the system

Question 45

A leaky suction valve can usually be detected by

Answer 45

any of the above

Question 46

Too low suction pressure could be caused by

Answer 46

any of the above

Question 47

What do you call a system in which the evaporator coils are located in a brine solution and the brine is pumped through the icebox?

Answer 47

an indirect system

Question 48

Before securing a compressor to do maintenance work in it, be sure to

Answer 48

purge the system pump down the system

Question 49

Obstruction of the expansion valve us usually caused by

Answer 49

any of the above

Question 50

Excess frost on the evaporator coils

Answer 50

reduces efficiency of the plant

Question 51

Air circulation in the icebox is accomplished by the use of which of the following?

Answer 51

diffuser fans

Question 52

The cooling water side of the condenser should be opened for inspection every

Answer 52

three months