TPC 436

Question 1

In a cooling system, one of the main lines in the piping system is the _________ line.

Answer 1

Liquid

Question 2

Steel pipe is typically joined by means of:

Answer 2

Flanges

Question 3

Tubing is often preferred over piping in a cooling system, because it:

Answer 3

Absorbs vibration better

Question 4

Refrigeration tubing is typically joined by:

Answer 4

Soldering

Question 5

When brazing tubing to a fitting, you should first heat the ______ until the ______ melts.

Answer 5

Tubing; flux

Question 6

The function of the discharge line in a refrigeration system is to:

Answer 6

Convey the refrigerant to the condenser

Question 7

The “entrainment” of compressor oil is the ______ the moving refrigerant.

Answer 7

Drawing in and transporting of oil with

Question 8

In order to keep entrained oil droplets moving through the piping, the refrigerant must move at ______ fpm in horizontal piping and ______ fpm in a vertical riser.

Answer 8

500 to 700; 750 to 1,500

Question 9

Refrigerant can be prevented from collecting in the compressor during the off-cycle by installing a(n) _______ in (on) the ________.

Answer 9

Check valve; discharge line

Question 10

Accessories often added to a discharge line include a(n):

Answer 10

Discharge muffler

Question 11

Subcooling is desirable in the liquid line, because it:

Answer 11

Reduces the volatility of the refrigerant

Question 12

If the pressure in the liquid line drops, flash gas can form, which can reduce the:

Answer 12

Refrigerating effect

Question 13

With halocarbon refrigerants, the movement of oil is better in the liquid line than in the discharge line, because the:

Answer 13

Oil is miscible in most liquid refrigerants

Question 14

A liquid receiver is used to:

Answer 14

Store all the refrigerant during repairs

Question 15

The purpose of a solenoid valve in the liquid line is to stop the flow of refrigerant to the:

Answer 15

Evaporator

Question 16

A double suction riser installed in a cooling system enables the system to operate at maximum load without creating excessive ________ in the suction line.

Answer 16

Pressure drop

Question 17

An accumulator in the suction line traps oil and liquid refrigerant to keep it from entering the ______. A heater in the accumulator evaporates the ______.

Answer 17

Compressor; refrigerant

Question 18

An evaporator-pressure regulator valve closes part way if the pressure at the evaporator outlet becomes too ______. A crankcase-pressure regulator valve closes part way if pressure at the compressor inlet becomes too ________.

Answer 18

Low; high

Question 19

The suction line is insulated in order to prevent or reduce ______ the line.

Answer 19

Condensation on the outside of

Question 20

The amount of oil that can build up in the suction line of an idle single-compressor system is much ______ than the amount that can build up in an idle compressor of a multiple-compressor system. To prevent damage from excessive oil buildup, the suction line should include a trap with the minimum rise of ______ in.

Answer 20

Less; 14

Question 21

Piping problems that result in operating problems are often caused by

Answer 21

Liquid hammer

Question 22

Which of the following expansion joints can be used in a refrigerant line?

Answer 22

Bellows

Question 23

Which kind of support is appropriate for a horizontal piping run of 15 feet long?

Answer 23

Rod-type hanger

Question 24

The problems caused by vibration in the piping of a cooling system include:

Answer 24

Damage to the valves and controls

Question 25

Insulation is needed on the liquid line if the line is ______ than its surroundings. The purpose of insulation on the liquid line is to prevent the loss of any ______ of the refrigerant.

Answer 25

Much colder; subcooling