网友您好， 请在下方输入框内输入要搜索的题目：
题目内容
（请给出正确答案）
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
参考答案
参考解析
解析：
暂无解析
更多 “单选题Most pump manufacturers recommend that the suction piping dimension for centrifugal pumps be （）.A one size smaller than the pump suction nozzleB the same size as the pump suction nozzleC one size larger than the pump suction nozzleD installed with a short radius elbow at the pump” 相关考题
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
考题
If a centrifugal pump is driven by a constant speed electric motor and produces a discharge pressure less than designed, the cause is probably ______.A.excessive pump speedB.excessive suction headC.worn wearing ringsD.gross pump misalignment
考题
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
考题
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
考题
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
考题
单选题What is a function of the wearing rings used in most centrifugal pumps?（）A
Absorb erosion of high velocity discharge streamB
Seal pump shaft against entry of airC
Isolate the discharge side from the suction sideD
Dampen the turbulent discharge flow
考题
单选题If you heard a ‘crackling’ noise in centrifugal pump, the most probable cause of the problem would be（）A
insufficient speedB
cavitationC
excess discharge pressureD
excessive net positive suction head B
考题
单选题A double suction centrifugal pump impeller has been installed in the reverse direction, and will （）.A
have a greater head capacityB
operate with increased impeller efficiencyC
discharge through the suction side of the pump casingD
require more power to run the shaft
考题
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.A
filledB
evacuatedC
compressedD
charged
考题
单选题The static suction lift of a pump is the difference in elevation between the （）.A
centerline of the pump and the level of the liquid in the suction well when the source of liquid is below the pumpB
centerline of the pump and the suction liquid level when the source of liquid is above the pumpC
centerline of the pump and the level of the discharge liquidD
liquid levels of the suction and discharge
考题
单选题Most pump manufacturers recommended that the discharge piping for centrifugal pumps be （）.A
one size larger than the pump discharge nozzleB
the same size as the pump discharge nozzleC
one size smaller than the pump discharge nozzleD
installed with a short radius elbow at the pump
考题
单选题Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.A
cavitationB
electrolysisC
abrasionD
corrosion
考题
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 （）.A
diameter of the discharge piping, with all other factors remaining the sameB
diameter of the suction piping, with all other factors remaining the sameC
width of the impeller onlyD
diameter of the impeller
考题
单选题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
考题
单选题A pump is said to have "negative suction head" when the pump is located （）.A
between the suction and dischargeB
below the liquid supplyC
above the liquid supplyD
any of the above
考题
单选题What does the term head mean when applied to a fire pump?（）A
Length of the discharge pipeB
Height of the discharge pipeC
Difference between the discharge and suction pressuresD
Sum of discharge and suction pressures
考题
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（）.A
excessive pump speedB
excessive suction headC
worn wearing ringsD
gross pump misalignment
考题
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 （）.A
head capacity to improveB
discharge to be reversedC
efficiency to decreaseD
slippage to decrease
考题
单选题In order to properly remove air from the casing of a centrifugal pump when starting, the pump should have a （）.A
positive headB
negative suction headC
mechanical sealD
vent valve attached to the casing at the top of the volute
考题
单选题A relief valve for a cargo pump is generally installed（）.A
after the discharge valveB
between the pump and discharge valveC
after the suction valveD
between the pump and suction valve
考题
单选题The static suction head of is the （）A
distance of the suction liquid level above the line of the pumpB
distance the suction liquid level is below the center line of the pumpC
force necessary to overcome frictional losses in the pump and pipingD
amount in inches of mercury the total suction head is below atmospheric pressure
考题
单选题Excessive air leakage into the suction side of a centrifugal pump would be indicated by which of the following operational problems?（）A
The pump delivers full capacity when started, but gradually slackens off toan abnormally low flowB
The pump packing gland overheats after short operating periodsC
The motor over-current protective device continually shuts the pump downD
Pounding noises can be heard at the pump suction chest
考题
单选题The time of discharging oil is short, but oily water separator discharges oil frequentlyThe possible reason is （）A
the sensor of low oil level is fully covered by sludgeB
the coarse strainer before the pump in suction system is cloggedC
the screw pump is worn seriously and volumetric efficiency is decreasedD
bilge suction value is clogged
考题
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 （）.A
the circuit breakerB
for leaks in the suction pipingC
relief valve is not properly seatedD
the suction strainer
考题
单选题Which of the following conditions could cause the feed pump for an auxiliary boiler to lose suction?（）A
Increased suction head pressureB
Decreased feedwater temperatureC
Pump recirculating line being open too muchD
Excessive feedwater temperature
考题
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?（）A
The wearing rings are excessively wornB
The suction strainer is cloggedC
The discharge valve is cloggedD
The shaft is worn
考题
单选题A simple pumping system consists of a suction branch, a pump and （）.A
a priming deviceB
a discharge branchC
a filterD
a suction valve
热门标签
最新试卷