更多"The compressor suction line conveys"的相关试题:
[单项选择]A warmer than normal compressor suction line might be caused by （）.
A. insufficient lubrication
B. insufficient refrigerant
C. excess refrigerant
D. excessive opening of the expansion valve
[单项选择]A bilge suction line，in a fishing vessel with more than 16 individuals aboard，must have a strainer with an open area not less than how many times the open area of the suction line?（）
A. one
B. two
C. three
D. four
[单项选择]If a refrigeration system were short of refrigerant, the condition would result in （）.
A. continuous running of the compressor
B. high suction pressure
C. high discharge pressure
D. short cycling of the compressor on the water failure switch
[单项选择]Refrigeration system compressor crankcase sweating is an indication of （）.
A. insufficient lube oil circulating through the system
B. excessive circulation of lube oil through the system
C. insufficient refrigerant in the system
D. an overworked compressor
[单项选择]Most pump manufacturers recommend that the suction piping dimension for centrifugal pumps be （）.
A. one size smaller than the pump suction nozzle
B. the same size as the pump suction nozzle
C. one size larger than the pump suction nozzle
D. installed with a short radius elbow at the pump
[单项选择]If the suction pressure at the refrigeration compressor is below normal, the cause can be（）.
A. refrigerant overcharge
B. overfeeding by the expansion valve
C. a restricted suction strainer
D. due to short cycling of the compressor
[单项选择]（）conveys a signal of desired rudder angle from the bridge and activates the power unit and transmission system unit the desired angle is reached.
A. The control equipment
B. The power unit
C. The transmission system
D. The follow-up mechanism
[单项选择]The emergency bilge suction or bilge injection valve is used to prevent （） of the ship.
A. proceeding
B. overloading
C. collision
D. flooding
[单项选择]The emergency bilge suction valve is typically used （）.
A. to inject cleaning additives when the bilges are extremely dirty
B. when the main condenser becomes fouled, in order to provide additional cooling water circulation
C. to connect the rose box to the independent bilge suction
D. if the bilges become flooded and they can not be emptied by any other means
[单项选择]Badly leaking refrigeration compressor discharge valves will cause（）.
A. overfeeding of the expansion valve
B. damage to the condenser
C. constant running of the compressor
D. flooding of the receiver
[单项选择]If a refrigeration compressor is running continuously without lowering temperature as normal in the refrigerator, the trouble may be （）.
A. excessive condenser cooling water
B. warm food in the refrigerator
C. a shortage of refrigerant
D. s shortage of compressor oil
[单项选择]Refrigerant entering the compressor of a refrigeration system should be in which of the following conditions?（）
A. Sub-cooled liquid
B. Sub-cooled vapor
C. Superheated vapor
D. Liquid
[单项选择]Sweating of the refrigeration system compressor crankcase is caused by （）.
A. too much superheat
B. insufficient superheat
C. suction pressure too low
D. excessive refrigerant returning to the compressor
[单项选择]Generally speaking, suction heads require to be （） for high speed or large capacities than for low speed or small capacities.
A. greater
B. smaller
C. better
D. worse
[单项选择]A simple pumping system consists of a suction branch, a pump and （）.
A. a priming device
B. a discharge branch
C. a filter
D. a suction valve
[单项选择]When operating with a negative suction head, which of the following types of pumps will require priming?（）
A. Reciprocating
B. Centrifugal
C. Rotary
D. Gear
[单项选择]It is possible to mount a double suction centrifugal pump impeller with the vanes facing in the wrong directionThis would cause the pump （）.
A. head capacity to improve
B. discharge to be reversed
C. efficiency to decrease
D. slippage to decrease
[单项选择]In the suction stroke, the crankshaft is rotating clockwise and the piston is moving （） the cylinderThe inlet valve is （） and a fresh charge of air is being drawn or pushed into the cylinder by the turbocharger.
A. up；opened
B. down；open
C. up；closed
D. down；closed
[单项选择]The static suction head of is the （）
A. distance of the suction liquid level above the line of the pump
B. distance the suction liquid level is below the center line of the pump
C. force necessary to overcome frictional losses in the pump and piping
D. amount in inches of mercury the total suction head is below atmospheric pressure
