A.removing all but the frictional load during starting
B.relieving intercoolers of high temperature buildups
C.providing high starting torque in the drive motor
D.seating valve plates during compressor shutdown
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A.loose expansion valve control bulb
B.low differential setting on the H-Pcutout
C.blown fuse in the motor circuit
D.faulty suction pressure regulator
A.prevent an internal explosion in the pump when it is overheated
B.enable a visual inspection of the pump while it is running
C.insure a proper alignment of the pump coupling to the driver
D.accommodate for friction between the impeller and the easing
A.explosive range
B.flash point
C.ignition temperature
D.combustion temperature
A.the pressure regulating valve is not closing
B.an excessive lack of refrigerant in the system
C.badly leaking discharge valves
D.worn piston rings
A.Both are higher than normal burning temperatures
B.The flash point is always higher
C.The ignition temperature is always higher
D.They are not necessarily related
A.tend to twist about its long axis
B.expand in length and in diameter
C.contract in length and expand in diameter
D.flex at right angles to the applied pressure
A.holding the discharge valve open
B.relieving the intercooler pressure to the atmosphere
C.using an enlarged, permanently opened clearance expansion space
D.a pre-charged accumulator
A.within the space concerned
B.outside the space concerned
C.the throttle station
D.within the fire room
A.leaking discharge valve
B.jammed suction valve
C.tripped overload relay
D.broken discharge un-loader
A.Liquids should never be transferred between tanks without consulting the dock master
B.If sea valves have been disassembled, all bonnets must be checked for leakage when the ship is re-floated
C.Before re-floating, all sea chest strainers should be verified as having been replaced
D.All of the above
最新试题
A pressure drop through the refrigerant liquid line may cause （）.
Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.
If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.
The major source of chemical contaminants in hydraulic fluid is （）.
Which of the problems listed would came the discharge temperature of an R-12 refrigeration compressor to increase?（）
Low compressor head pressure in a refrigeration system can be caused by（）.
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 （）.
If the thermal bulb of an expansion valve is incorrectly placed at the center of the coil instead of the end, it will （）.