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）
What is the purpose of pressure-vacuum relief valves ________．
A.Regulation of discharge pressure from cargo pumps
B.Maintaining constant velocity in cargo lines
C.Regulation of suction head on cargo pumps
D.To maintain a tank or void at atmospheric pressure
参考答案
更多 “ What is the purpose of pressure-vacuum relief valves ________．A.Regulation of discharge pressure from cargo pumpsB.Maintaining constant velocity in cargo linesC.Regulation of suction head on cargo pumpsD.To maintain a tank or void at atmospheric pressure ” 相关考题
考题
After installing a new hydraulic pump in a system, what special attention should be given to the hydraulic system?A.The relief valves in the system should be readjustedB.The filters and strainers should be checked frequentlyC.All system pressure should be readjustedD.The system should be drained and renewed with a fluid of different operating characteristics
考题
Badly leaking refrigeration compressor discharge valves will cause ______.A.overfeeding of the expansion valveB.damage to the condenserC.constant running of the compressorD.flooding of the receiver
考题
How should cargo tank hatches be protected when the ullage opening is open and the tank NOT gas free?A.With gooseneck ventsB.With warning signsC.With flame screensD.With pressure-vacuum relief valves
考题
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
考题
What is the purpose of the relief valve of a cargo pump ________．A.Provides for the removal of vaporsB.Allows two or more tanks to be filled at the same timeC.Provides for the emergency shutdown of the pumpD.Permits the return of cargo to the suction side of the pump
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
单选题What is the purpose of pressure-vacuum relief valves? （）A
Regulation of discharge pressure from cargo pumpsB
Maintaining constant velocity in cargo linesC
Regulation of suction head on cargo pumpsD
To maintain a tank or void at atmospheric pressure
考题
单选题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
单选题The purpose of the safety relief valves installed on an auxiliary boiler is to （）.A
relieve excess fuel oil pressure during the “off” fire cycleB
admit water to the dry pipeC
throttle the forced draft fan output for proper combustionD
reduce excess steam pressure in the boiler
考题
单选题After installing a new hydraulic pump in a system, what special attention should be given to the hydraulic system?（）A
The relief valves in the system should be readjustedB
The filters and strainers should be checked frequentlyC
All system pressure should be readjustedD
The system should be drained and renewed with a fluid of different operating characteristics
考题
单选题Badly leaking refrigeration compressor discharge valves will cause（）.A
overfeeding of the expansion valveB
damage to the condenserC
constant running of the compressorD
flooding of the receiver
考题
单选题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
考题
单选题If the discharge valves on a refrigeration compressor are leaking badly, the compressor should （）.A
run continuouslyB
not startC
have high discharge pressureD
short cycle on the high pressure switch
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Overload protection on hydraulic system is provided by the use of （）.A
stop valvesB
pressure relief valvesC
balance valvesD
regulating speed valves
考题
单选题The usual symptoms of cavitation in a centrifugal pump is （）.A
noise and vibrationB
an increase in discharge pressureC
an increase in suction pressureD
lifting of the relief valve
考题
单选题Blow-off of the relief valves of the engines cylinders may be caused by （）.A
too low leadB
water in fuelC
too tight springD
leakage
考题
单选题What is the purpose of the intake/exhaust valves in a diesel engine? （）A
They regulate the combustion cycleB
They supply cooling waterC
They synchronize the ignition sparkD
They supply and regulate the lubricant flow
考题
单选题To operate a centrifugal fire pump at reduced capacity, you should （）.A
readjust the relief valveB
throttle the suction lineC
throttle the discharge valveD
open the priming line
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Bad valves operation of the reciprocating air compressors can be detected by observation of （）.A
the discharge temperature lowB
the discharge temperature highC
the discharge pressure riseD
the inter-stage pressure low
考题
单选题What is the purpose of a relief valve?（）A
to fill 2 tanks at the same timeB
to use pump at a higher pressureC
to return liquid to suction side if discharge valve is closedD
All of the above are true
考题
单选题The major difference between the discharge and suction valves installed in most low pressure, reciprocating air compressors is that（）A
one valve seats upwards, while the other seats downwardsB
the reed valves used on the discharge are made substantially thicker and heavier than the suction valvesC
the suction valve springs exert a greater tension than the discharge valve springsD
the discharge valve springs exert a greater tension than the suction valve springs
考题
单选题Excessively low air pressure occurring in the intercooler of a reciprocating air compressor is caused by（）.A
leaky discharge valves on the LP cylinderB
leaky discharge valves on the HP cylinderC
insufficient intercooler coolingD
low ambient air pressure
考题
单选题How should cargo tank hatches be protected when the ullage opening is open and the tank not gas free?（）.A
With gooseneck ventsB
With warning signsC
With flame screensD
With pressure-vacuum relife valves
考题
单选题A spur gear pump should be operated with the discharge valves （）.A
slightly openedB
throttledC
fully openedD
halfway opened
考题
单选题A device fitted over the discharge opening on a relief valve consisting of one or two woven wire fabrics is called a flame（）.A
stopperB
screenC
filterD
restrictor
热门标签
最新试卷