436 Flashcards

(25 cards)

1
Q

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

A

Liquid

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2
Q

Steel pipe is typically joined by means of

A

Flanges

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3
Q

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

A

absoros vibration better

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4
Q

Refrigeration tubing is typically joined by

A

Soldering

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5
Q

When brazing tubing to a fitting, vou should first heat the _____ until the ______ melts

A

Tubing, flux

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6
Q

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

A

convey the refrigerant to the condenser

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7
Q

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

A

drawing in and transporting of oil with

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8
Q

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

A

500 to 700: 750 to 1 500

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9
Q

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

A

check valve, discharge line

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10
Q

Accessories often added to a discharge line include a

A

Discharge muffler

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11
Q

Subcooling is desirable in the liquid line, because it

A

reduces the volatility of the refrigerant

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12
Q

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

A

refrigerating effect

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13
Q

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

A

oil is miscible in most liquid refrigerants

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14
Q

A liquid receiver is used to

A

store all the refrigerant during repairs

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15
Q

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

A

Evaporator

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16
Q

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

A

Pressure drop

17
Q

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

A

compressor, refrigerant

18
Q

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 _____

19
Q

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

A

condensation on the outside of

20
Q

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.

21
Q

Piping problems that result in operating problems are often caused by

A

Liquid hammer

22
Q

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

23
Q

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

A

Rod-type hanger

24
Q

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

A

Damage to the valves and controls

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
much colder, subcooling