更多"In （） pumps a closed discharge valv"的相关试题:
[单项选择]In （） pump a closed discharge valve will not cause excessive pressure to build up.
A. gear
B. vane
C. screw
D. centrifugal
[单项选择]If the discharge valve is closed before the drive motor is stopped, which of the following types of pumps will most likely be damaged?（）
A. Centrifugal
B. Gear
C. Propeller
D. Turbine
[单项选择]Gear pumps are of positive displacement type pumps because they discharge a near constant amount of liquid （） pressure.
A. depending on
B. in relative to
C. regardless of
D. because of
[单项选择]Increasing the valve clearance between a valve stem and rocker arm, will result in the valve （）
A. closing later
B. opening sooner
C. staying open for a shorter period of time
D. staying open for a longer period of time
[单项选择]The needle valve in a fuel valve will （） when the fuel pressure action on the needle valve tapered face exerts a force lower than that of the spring compression.
A. be jammed
B. be opened
C. be seated
D. be broken
[单项选择]Positive displacement, helical gear pumps are well suited for pumping oil because （）
A. stuffing boxes eliminate the leakage problems usually associated with other gear pumps
B. it is not necessary to closely maintain design clearances with this pump
C. they are essentially self-priming and produce a high suction lift
D. these pumps are designed with extreme tooth angled
[单项选择]Hydraulic pumps most commonly used in steering systems are of the （）.
A. lobe type
B. screw type
C. axial piston type
D. volute type
[单项选择]Overgreasing of ball bearings installed on pumps will result in （）.
A. smoother pump operation
B. overheating of the bearing
C. reduced corrosion in the bearing
D. increased pump capacity
[单项选择]Regulations require that cargo pumps in tankers carrying grade D liquid cargo shall be isolatedfrom sources of vapor ignition by（）.
A. cofferdams
B. gastight bulkheads
C. passageways or living quarters
D. general cargo spaces
[单项选择]Cooling water pumps driven by direct reversing diesel engines are usually of the straight impeller vane type pump with a concentric housing to（）
A. facilitate bi-directional operation
B. provide the greatest pump efficiency
C. prevent pump clogging from marine growth
D. prevent cavitation at the pump outlet
[单项选择]Which of the following pumps belongs to centrifugal pump?（）
A. Piston pump
B. Screw pump
C. Diffuser pump
D. Water-ring pump
[单项选择]Centrifugal pumps are popular because they are very simple in construction,and produce smooth, constant, （） discharge.
A. non-pulsating
B. pulsating
C. positive
D. non-positive
[单项选择]When fire pumps are used for other than firefighting service，each pipe connecting the other service (except for branch lines used for deck washing) must have a（）.
A. check valve installed in the line
B. shut off valve at a manifold near the pump
C. quick disconnect union within ten feet of the pump
D. regulator in the line set at 125 psi
[单项选择]Multiple fire pumps may be used for other purposes provided that one pump is（）.
A. on line to the fire main
B. kept available for use on the fire main at all times
C. capable of being connected to the fire main
D. rated at or above 125 psi
[单项选择]Under centrifugal pumps are the volute, diffuser, mixed-flow, axial flow and （） or regenerative types.
A. reciprocating
B. hydraulic
C. turbine
D. vane
[单项选择]Which of the following pumps will most affect oily water separator performance and give the worst result?（）
A. reciprocating pump
B. vane pump
C. screw pump
D. centrifugal pump
[单项选择]Which of the following pumps is most suitable for an oily water separator?（）
A. reciprocating pump
B. vane pump
C. mono pump
D. axial-flow pump
[单项选择]Centrifugal pumps can be designed with a number of impellers （） to attain a high final delivery pressure.
A. in series
B. in parallel
C. either A or B
D. None of the above is tree
