单选题The gear and screw pumps are classified as （）.Avariable stroke pumpsBmultistage pumpsCpositive displacement pumpsDtriple-ported pumps
单选题
The gear and screw pumps are classified as （）.
A
variable stroke pumps
B
multistage pumps
C
positive displacement pumps
D
triple-ported pumps
参考解析
解析：
暂无解析
相关考题：
Gear pumps are widely used to transfer any one of the following but .A.fuel oilB.lube oilC.hydraulic oilD.fresh water
Which statement is NOT true?A.In a simple vane pump, the rotor and cam ring are exactly concentricB.Balanced vane pump has an elliptical cam ringC.Liquid in both gear pump and vane pump are forced out to the outlet.D.Balanced vane pumps can work at a higher pressure than the simple vane pump
Dual electro-hydraulic steering units usually operate ______．A.With both pumps on line at the same timeB.With one pump on standbyC.With the follow-up gear disconnectedD.Only when the rudder is moved amidships
When the helm is turned on the navigation bridge，which of the listed actions will be the FIRST response in the steering room on a ship equipped with an electro-hydraulic steering gear ________．A.The pumps go to full strokeB.The six-way valve aligns itself with the running pumpC.Both port and starboard cables are energizedD.The synchronous receiver turns，duplicating the helm motion
A technician is trying to retrieve a screw that fell inside a case and is just out of reach. Which of the following is the BEST procedure to retrieve the screw?（）A、Turn the case upside down, shake gently and let the screw fall out.B、Use a shop vacuum to retrieve the screw.C、Use the hardware abstraction layer (HAL).D、Use an extension magnet.
单选题A gear pump belongs to （） according to its working principle.Areciprocating pumpsBpositive displacement pumpsCcentrifugal pumpsDcentripetal pumps
单选题Which of the following pumps are self-priming, and can deal with liquid from a level below the pump（） (1) ejector (2) screw (3) centrifugalA(1)onlyB(1)and(2)C(1),(2)and(3)D(2)and(3)
单选题A twin-screw vessel is easier to maneuver than a single-screw vessel because the twin-screw vessel（）.Apermits the rudder to move fasterBgenerates more powerCcan turn without using her rudderDcan suck the water away from the rudder
单选题A screw pump belongs to （） according to its working principle.Areciprocating pumpsBpositive displacement pumpsCcentrifugal pumpsDcentripetal pumps
单选题Gear pumps are of positive displacement type pumps because they discharge a near constant amount of liquid （） pressure.Adepending onBin relative toCregardless ofDbecause of
单选题Which of the following statements represents the advantage of rotary pumps as compared to reciprocating pumps?（）AThe high discharge pressure of the rotary pumps permits a larger volume of fluid per unit time than the reciprocating pumpBRotary pumps are capable of pumping more fluid than reciprocating pumps of the same weightCRotary pumps occupy only one-half the space of reciprocating pumpsDRotary pumps eliminate discharge slippage of the pumped liquid, while this does not hold true for a reciprocating pump
单选题The gear, screw, and vane pumps are all classified as （）.Avariable stroke pumpsBmultistage pumpsCpositive displacement pumpsDtriple-ported pumps
单选题The pumps employed on board ship can be divided into two main categories ie（） pumps and centrifugal pumps.AgearBnonpositive displacementCpositive displacementDrotary
单选题Positive displacement, helical gear pumps are well suited for pumping oil because （）Astuffing boxes eliminate the leakage problems usually associated with other gear pumpsBit is not necessary to closely maintain design clearances with this pumpCthey are essentially self-priming and produce a high suction liftDthese pumps are designed with extreme tooth angled
单选题（） connected to the moving tiller will bring the floating lever pivot and the lever into line at right angles to the screw shaft axis.AA cut-off leverBA swivel blockCA cross-headDA driving gear
单选题In a （） the center screw is driven and the outer screws idle.Asingle screw pumpBdouble-screw pumpCtriple screw pumpDcentripetal pump
单选题Which of the following pumps will build up a bursting pressure or stall their motors if the discharge valves are closed?（） (1) gear (2) centrifugal (3) screwA（1）and（2）B（1），（2）and（3）C（1）and（3）D（2）and（3）
单选题Dual electro-hydraulic steering units usually operate （）.Awith both pumps on line at the same timeBwith one pump on standbyCwith the follow-up gear disconnectedDonly when the rudder is moved amidships
单选题Under rotary pumps are the gear, （）, cam-and-piston and screw types.AreciprocatingBdiffuserCturbineDvane
单选题Gear pumps are （） type because they discharge a near constant amount of liquid regardless of pressure.Apositive displacementBnon-positive displacementCmixed-flowDaxial-flow
单选题Which of the following statements is/are true regarding hydraulic pumps in general? （）AVariable volumes can be obtained with gear pumps only by variation of the pump drive speedBA radial piston pump houses sliding pistons in a stationary cylinder block through which passes a rotating pintle or ported shaftCThe amount of fluid displaced per revolution of an axial piston rotary pump is dependent on the angle formed between the cylinder block and valve plateDAll of the above
单选题The cylinder covers and the liners are bolted together by means of studs （） the cylinder frames.Ascrewing intoBbeing screw onCto screw onDscrewed into
单选题One of the main differences between the various types of screw pumps is in the （）.Astuffing box diameterBdirection of rotation of the screwsCpitch of the screwsDtype of driving gears
单选题When turning a ship in restricted space with a strong wind，it is normally best to（）.AGo ahead on both engines with the rudder hard to one side，if on a twin-screw vesselBBack down with the rudder hard to one side，if on a single-screw vesselCTake advantage of the tendency to back to port，if on a twin-screw vesselDTurn so that the tendency to back into the wind can be used，if on a single-screw vessel
单选题On a vessel making a voyage more than 48 hours long，regulations require that（）.Aa lifeboat drill be held within 12 hours prior to departureBfire pumps be tested by starting within 12 hours prior to departureCthe emergency generator and lighting system be tested by starting and operating within 12 hours prior to departureDthe entire steering gear be tested within 12 hours prior to departure
单选题The gear and screw pumps are classified as （）.Avariable stroke pumpsBmultistage pumpsCpositive displacement pumpsDtriple-ported pumps