更多"The pressure head of a water pump i"的相关试题:
[单项选择]The pressure head of a pump is given in the unit of （）.
A. kg
B. MPa
C. meter fluid column
D. None of the above is true
[单项选择]A water pump can not supply water after startingIt may be caused by （）.
A. closed discharge valve
B. broken pipe line
C. worn shaft
D. both A and B
[单项选择]In a domestic fresh water system, the pump starters are controlled by （） switches which operate when the pressure in the tank varies within predetermined limits as water is drawn off.
A. water level
B. water flow
C. temperature
D. pressure
[单项选择]The domestic fresh water pump starters are controlled by pressure switches which operate when the pressure in the tank varies within predetermined limits as water is drawn offThe word “which” means （）.
A. starters
B. pressure switches
C. pressure
D. water
[单项选择]The pressure of a liquid leaving the pump can be referred to as the （）.
A. total head
B. discharge head
C. net positive suction head
D. suction head
[单项选择]Domestic water pump is started automatically by （） which operates as the water level falls to a predetermined level.
A. a level controller
B. a temperature switch
C. a pressure switch
D. a floating ball
[单项选择]A centrifugal pump produces the required pressure energy by means of a rotating （） provided with vanes.
A. propeller
B. impeller
C. circumference
D. screw
[单项选择]Because the flow rate of supply water pump is too large, oily water separator does not work wellWhich of the following is not the reason?（）
A. the monitoring equipment is out of order
B. separating effect becomes bad
C. inner wall is contaminated
D. separating effect becomes bad and inner wall is contaminated
[单项选择]The motor for the fresh water pump （）.
A. need to repair
B. need to be repaired
C. needs to repair
D. needs repairing
[单项选择]The boiler feed pump discharge pressure is higher than the steam drum pressure to （）.
A. ensure feed water flow into the boiler
B. keep the steam drum pressure high
C. prevent water hammer in the feed line
D. help the feed water flash to steam
[单项选择]The pump discharge pressure will be considerably higher than the pressure at the （）.
A. pump entry branch
B. outlet pipe
C. impeller
D. None of the above is true
[单项选择]The discharge head of a centrifugal pump will vary directly with the （）.
A. change in impeller diameter
B. square of the impeller diameter
C. cube of the impeller diameter
D. impeller efficiency for large changes in the size of the impeller
[单项选择]The upward pressure of displaced water is called（）.
A. buoyancy
B. deadweight
C. draft
D. freeboard
[单项选择]Low compressor head pressure in a refrigeration system can be caused by（）.
A. insufficient condenser cooling water
B. excessive condenser cooling water
C. air in the refrigeration system
D. excessive refrigerant in the system
[单项选择]If the head pressure of a reciprocating refrigeration compressor is excessive, （）.
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
[单项选择]An increasing head pressure in a refrigeration system, without any corresponding change in the cooling water inlet temperature, would probably be caused by （）.
A. restriction in refrigerant piping
B. air and non-condensable gases in the condenser
C. water in the refrigerant
D. flooding back of liquid refrigerant from the evaporator
[单项选择]The most suitable pump for oily water separator feed duties is （）.
A. a reciprocating pump
B. a vane pump
C. a centrifugal pump
D. a triple screw pump
[单项选择]A centrifugal pump may fail to deliver water when first started if the （）.
A. water seal pipe is plugged
B. pump is not primed
C. seal ring is improperly located
D. impeller is flooded
[单项选择]Each fire pump on a ship must have a pressure gauge located at（）.
A. the pump discharge
B. the manifold connection
C. each fire station discharge
D. the pump station
