A.reciprocating pump
B.positive displacement pump
C.centrifugal pump
D.centripetal pump
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A.dead band action
B.neutral zone action
C.range
D.on-off action
A.the relief valve should open before the high pressure cutout
B.the relief valve should open and allow the excess refrigerant to flow to the receiver
C.the high pressure cutout switch should operate before the relief valve opens
D.you should close in on the suction valve
A.Cross
B.Parallel
C.Counter
D.Circular
A.insufficient cooling water flow to the condenser
B.a low refrigerant charge in the system
C.the liquid valve is open too much
D.high evaporator superheat
A.add fluid that is the same color as the fluid in the reservoir
B.add turbine oil because it is always a good substitute
C.add any oil that has the same viscosity as the hydraulic fluid
D.check the winch manufacturers instruction book
A.Centrifugal
B.Reciprocating
C.Gear
D.Rotary
A.cause of salt contamination
B.location of salt water contamination
C.chemical makeup of feed-water
D.level of alkalinity in condensate
A.check hydraulic oil levels every hour
B.check the rams for overheating
C.check for excessive oil leakage from rams
D.drain water from telemotor cylinders each watch
A.suction pressure only
B.head pressure only
C.superheat only
D.suction pressure and box temperature
A.increase the amount of cooling water to the condenser
B.decrease the amount of cooling water to the condenser
C.add more refrigerant to the system
D.remove some refrigerant from the system
最新試題
One cause of high head pressure occurring in a refrigeration system can be （）.
The general purpose of a heat exchanger is to （）.
An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.
Who is responsible for ensuring that someone is assigned to close the watertight doors in an emergency?（）
The control mode in which the final control element is moved from one of two flexed positions to the other is known as （）.
A salinity indicator is used to determine the （）.
Which of the listed pumps is NOT a positive displacement pump?（）
On tank vessels equipped with power operated cargo tank valves, the type of power operator most commonly used is （）.
Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.
The major source of chemical contaminants in hydraulic fluid is （）.