单选题Most pump manufacturers recommend that the suction piping dimension for centrifugal pumps be （）.Aone size smaller than the pump suction nozzleBthe same size as the pump suction nozzleCone size larger than the pump suction nozzleDinstalled with a short radius elbow at the pump
单选题
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
参考解析
解析：
暂无解析
相关考题：
Which of the following terms is used to identify the pressure of the liquid entering a pump?A.Suction headB.Pump headC.Discharge headD.Total head
If a centrifugal pump is driven by a constant speed electric motor and produces a discharge pressure less than designed, the cause is probably ______.A.excessive pump speedB.excessive suction headC.worn wearing ringsD.gross pump misalignment
Cargo pump relief valves are piped to the ______．A.cargo pump pressure gaugesB.crossover lines interconnecting two pumpsC.suction side of pumpsD.atmosphere through pump vents
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
You start a centrifugal cargo pump to discharge cargo．The pump works for a while and then loses suction．This could be caused by ______．A.The pump running backwardsB.Incomplete primingC.The discharge head being too highD.All of the above
单选题What is a function of the wearing rings used in most centrifugal pumps?（）AAbsorb erosion of high velocity discharge streamBSeal pump shaft against entry of airCIsolate the discharge side from the suction sideDDampen the turbulent discharge flow
单选题If you heard a ‘crackling’ noise in centrifugal pump, the most probable cause of the problem would be（）Ainsufficient speedBcavitationCexcess discharge pressureDexcessive net positive suction head B
单选题A double suction centrifugal pump impeller has been installed in the reverse direction, and will （）.Ahave a greater head capacityBoperate with increased impeller efficiencyCdischarge through the suction side of the pump casingDrequire more power to run the shaft
单选题Before liquid can flow into a pump, the air in the suction line must be （） sufficiently to cause the liquid to flow into the suction chamber.AfilledBevacuatedCcompressedDcharged
单选题The static suction lift of a pump is the difference in elevation between the （）.Acenterline of the pump and the level of the liquid in the suction well when the source of liquid is below the pumpBcenterline of the pump and the suction liquid level when the source of liquid is above the pumpCcenterline of the pump and the level of the discharge liquidDliquid levels of the suction and discharge
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Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.AcavitationBelectrolysisCabrasionDcorrosion
单选题Increasing the speed of a centrifugal pump will result in an increase in its capacity Another means of increasing the capacity of a centrifugal pump is to increase the （）.Adiameter of the discharge piping, with all other factors remaining the sameBdiameter of the suction piping, with all other factors remaining the sameCwidth of the impeller onlyDdiameter of the impeller
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A pump is said to have "negative suction head" when the pump is located （）.Abetween the suction and dischargeBbelow the liquid supplyCabove the liquid supplyDany of the above
单选题What does the term head mean when applied to a fire pump?（）ALength of the discharge pipeBHeight of the discharge pipeCDifference between the discharge and suction pressuresDSum of discharge and suction pressures
单选题If a centrifugal pump is driven by a constant speed electric motor and produces a discharge pressure less than designed, the cause is probably（）.Aexcessive pump speedBexcessive suction headCworn wearing ringsDgross pump misalignment
单选题It is possible to mount a double suction centrifugal pump impeller with the vanes facing in the wrong directionThis would cause the pump （）.Ahead capacity to improveBdischarge to be reversedCefficiency to decreaseDslippage to decrease
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The static suction head of is the （）Adistance of the suction liquid level above the line of the pumpBdistance the suction liquid level is below the center line of the pumpCforce necessary to overcome frictional losses in the pump and pipingDamount in inches of mercury the total suction head is below atmospheric pressure
单选题Excessive air leakage into the suction side of a centrifugal pump would be indicated by which of the following operational problems?（）AThe pump delivers full capacity when started, but gradually slackens off toan abnormally low flowBThe pump packing gland overheats after short operating periodsCThe motor over-current protective device continually shuts the pump downDPounding noises can be heard at the pump suction chest
单选题The time of discharging oil is short, but oily water separator discharges oil frequentlyThe possible reason is （）Athe sensor of low oil level is fully covered by sludgeBthe coarse strainer before the pump in suction system is cloggedCthe screw pump is worn seriously and volumetric efficiency is decreasedDbilge suction value is clogged
单选题If a bilge pump is able to develop vacuum, but is unable to sufficiently pump out the bilges, you would check for all of the following EXCEPT （）.Athe circuit breakerBfor leaks in the suction pipingCrelief valve is not properly seatedDthe suction strainer
单选题Which of the following conditions could cause the feed pump for an auxiliary boiler to lose suction?（）AIncreased suction head pressureBDecreased feedwater temperatureCPump recirculating line being open too muchDExcessive feedwater temperature
单选题If an operating bilge pump is developing good vacuum, but is unable to discharge any water, which of the following problems is the most probable cause?（）AThe wearing rings are excessively wornBThe suction strainer is cloggedCThe discharge valve is cloggedDThe shaft is worn
单选题A simple pumping system consists of a suction branch, a pump and （）.Aa priming deviceBa discharge branchCa filterDa suction valve