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 the 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 ariser

Answer 8

500 to 700; 750 to 1,500

Question 9

refrigerant can be prevented from collecting tin the compressor during the off cycle by installing a ___ in the ___

Answer 9

check valve ; discharge line

Question 10

accessories often added to a discharge line include a

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 mist 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 ____ inches

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