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

Diesel engines are started by supplying_____into the cylinders in the appropriate sequence for the required direction.

A.cooling water

B.compressing air

C.compressed air

D.cylinder oil

A fire pump may be used for other purposes if ______.

A.the other services are run off a reducing station with a pressure gage

B.one of the required pumps is kept available for use on the fire main system at all times

C.no relief valves are installed

D.all of the above conditions are met

Which of the listed pressure control valves would be used to establish the maximum operating pressure of a hydraulic system?

A.Pressure-reducing valve

B.Unloading valve

C.Counterbalance valve

D.Pressure-relief valve

Cargo pump relief valves are piped to the ______．

A.cargo pump pressure gauges

B.crossover lines interconnecting two pumps

C.suction side of pumps

D.atmosphere through pump vents

Rudder position is shown on the bridge by the .

A.rudder angle indicator

B.follow-up gear

C.telemotor position

D.relief valves

How should cargo tank hatches be protected when the ullage opening is open and the tank NOT gas free?

A.With gooseneck vents

B.With warning signs

C.With flame screens

D.With pressure-vacuum relief valves

Diesel engines are started by supplying into the cylinders in the appropriate sequence for the required direction.

A.cooling water

B.compressing air

C.compressed air

D.cylinder oil

All of the following steps are taken in starting a centrifugal pump，EXCEPT to ______．

A.Set the relief valve

B.Check the lubrication system

C.Vent the pump casing

D.Open the pump suction and discharge valves