436 Flashcards
(25 cards)
In a cooling system, one of the main lines in the piping system is the ____ line
Liquid
Steel pipe is typically joined by means of
Flanges
Tubing is often preferred over piping in a cooling system, because it
absoros vibration better
Refrigeration tubing is typically joined by
Soldering
When brazing tubing to a fitting, vou should first heat the _____ until the ______ melts
Tubing, flux
The function of the discharge line in a refrigeration system is to
convey the refrigerant to the condenser
The “entrainment” of compressor oil is the ______ the moving refrigerant
drawing in and transporting of oil with
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.
500 to 700: 750 to 1 500
Refrigerant can be prevented from collecting in the compressor during the off-cycle by installing a(n) _____ in (on) the _____
check valve, discharge line
Accessories often added to a discharge line include a
Discharge muffler
Subcooling is desirable in the liquid line, because it
reduces the volatility of the refrigerant
If the pressure in the liquid line drops, flash gas can form, which can reduce the
refrigerating effect
With halocarbon refrigerants, the movement of oil is better in the liquid line than in the discharge line, because the
oil is miscible in most liquid refrigerants
A liquid receiver is used to
store all the refrigerant during repairs
The purpose of a solenoid valve in the liquid line is to stop the flow of refrigerant to the
Evaporator
A double suction riser installed in a cooling system enables the system to operate at maximum load without creating excessive ______ in the suction line
Pressure drop
An accumulator in the suction line traps oil and liquid refrigerant to keep it from entening the _____. A heater in the accumulator evaporates the _____.
compressor, refrigerant
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 _____
low, high
The suction line is insulated in order to prevent or reduce ____ the line
condensation on the outside of
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.
Less, 14
Piping problems that result in operating problems are often caused by
Liquid hammer
Which of the following expansion joints can be used in a refrigerant line?
bellows
Which kind of support is appropriate for a horizontal piping run of 15 feet long?
Rod-type hanger
The problems caused by vibration in the piping of a cooling system include
Damage to the valves and controls