单选题When starting a centrifugal pump, the discharge valve should be （）.AclosedBopened fullyCcracked openDpartly open
单选题
When starting a centrifugal pump, the discharge valve should be （）.
A
closed
B
opened fully
C
cracked open
D
partly open
参考解析
解析：
暂无解析
相关考题：
Throttling in the _____ line of a centrifugal pump involves the risk of the pump cavitation.A.suctionB.exhaustC.pressureD.discharge
Which of the following will be the advantage of a centrifugal pump as compared with a reciprocating pump? l.Its discharge is continuous; ll.It has no internal valves: lll.Upon accidental closing of discharge valve, excessive pressure will not build up()A.l, llB.ll, lllC.l ,ll.IIID.llonly
A spur gear pump should be operated with the discharge valves ______.A.slightly openedB.throttledC.fully openedD.halfway opened
Which method should be used to warm up the pump turbines prior to discharge ________．A.Lock the turbine rotor and slowly bleed in steam until operating temperature is reachedB.Run the pump at high speed with the discharge valves closedC.Run the turbine at slow speed with the pump disconnectedD.Shut the discharge valve and run the pump at slow speed
All of the following steps are taken in starting a centrifugal pump，EXCEPT to ______．A.Set the relief valveB.Check the lubrication systemC.Vent the pump casingD.Open the pump suction and discharge valves
Her mother asked her to keep the windows___________and the doorA.opened ; closedB.open ; closedC.open ; closeD.opened ; close
单选题The usual symptoms of cavitation in a centrifugal pump is （）.Anoise and vibrationBan increase in discharge pressureCan increase in suction pressureDlifting of the relief valve
单选题To operate a centrifugal fire pump at reduced capacity, you should （）.Areadjust the relief valveBthrottle the suction lineCthrottle the discharge valveDopen the priming line
单选题A centrifugal pump attempting to develop flow against a closed discharge valve has a/an （）.Acapacity of 0%Befficiency of 100%Cinternal slippage of 0%Dshut off horsepower rating of 100%
单选题When start a screw pump, the by pass valve should be （）.AclosedBopened fullyCcracked openDpartly open
单选题If a centrifugal bilge pump were continually operated with the discharge valve closed the （）.Amotor overload would openBrelief valve would openCpump would eventually overheatDmotor would overheat
单选题When starting a reciprocating pump, the inlet valve should be （）.AclosedBopened fullyCcracked openDpartly open
单选题Which of the following will be the advantage of a centrifugal pump as compared with a reciprocating pump?（） (1) Its discharge is continuous (2) It has no internal valves (3) Upon accidental closing of discharge valve, excessive pressure will not build upA（1），（2）B（2），（3）C（1），（2），（3）D（2）only
单选题Most pump manufacturers recommended that the discharge piping for centrifugal pumps be （）.Aone size larger than the pump discharge nozzleBthe same size as the pump discharge nozzleCone size smaller than the pump discharge nozzleDinstalled with a short radius elbow at the pump
单选题When the starting air valve closes on one cylinder, another starting air valve has （） opened on another cylinder whose piston has just commenced its downward stroke.AjustBnearlyCmerelyDalready
单选题In order to properly remove air from the casing of a centrifugal pump when starting, the pump should have a （）.Apositive headBnegative suction headCmechanical sealDvent valve attached to the casing at the top of the volute
单选题Which of the listed statements is correct concerning the starting of centrifugal pumps?（）AThey should always be started with the discharge valve closedBThey should always be started with the discharge valve openedCA priming pump is always required to flood the impeller suctionDThey should always be started with the sealing line valves closed
单选题The advantage of a centrifugal pump as compared with a reciprocating pump is that （）.Adischarge is continuousBit has no internal valvesCupon accidental closing of discharge valve, excessive pressure will not build upDall of the above are true
单选题A relief valve for a cargo pump is generally installed（）.Aafter the discharge valveBbetween the pump and discharge valveCafter the suction valveDbetween the pump and suction valve
单选题If a centrifugal pump were continually operated with the discharge valve closed, the （）.Amotor controller overload would openBpump would eventually overheatCrelief valve would continuously cycle openDmotor would overheat
单选题When starting a centrifugal pump, the discharge valve should be （）.AclosedBopened fullyCcracked openDpartly open
单选题The valve on the discharge side of a cargo pump on a tanker will usually be a（）.Abutterfly valveBspectacle valveCcheck valveDglobe valve
单选题All of the following steps are taken in starting a centrifugal pump，EXCEPT to（）.Aset the relief valveBcheck the lubrication systemCvent the pump casingDopen the pump suction and discharge valves
单选题The simplest method to use for determining if a centrifugal pump is operating as designed, is to （）.Aclosely observe the pump discharge temperatureBclose off the discharge valve, and watch for a rise in pressureCmomentarily close off the suction valve, and watch for a rise in pressureDuse a clamp on ammeter and compare the readings to past records
单选题A spur gear pump should be operated with the discharge valves （）.Aslightly openedBthrottledCfully openedDhalfway opened
单选题A gradual decrease in the discharge pressure of an operating hydraulic pump can be caused by （）.Athe four-way control valve failing to shiftBthe bleeder valve sticking in the open positionCcold hydraulic fluidDa clogged air vent falter on the oil reservoir
单选题Which method should be used to warm up the pump turbines prior to discharge（）.ALock the turbine rotor and slowly bleed in steam until operating temperature is reachedBRun the pump at high speed with the discharge valves closedCRun the turbine at slow speed with the pump disconnectedDShut the discharge valve and run the pump at slow speed
单选题One of the consequences in continuing to operate a centrifugal bilge pump with the discharge valve closed, is that the （）.Amotor overload will openBrelief valve will openCpump will overheatDmotor will overheat