Auxiliary Machinery. Test 68 – Online Maritime Tests

The two valves on the left of this picture are _____ , the two valves on the right are _____ valves.

flat top, linear.
pear shaped, equi-percentage.
linear, equi-percentage.
linear, curved.

Why is the stern tube header tank fitted above the sea water level?

To prevent bilge water entering the stern tube.
Ensure lubrication of the after stern tube seal.
Ensure lubrication of the forward stern tube seal.
To avoid sea water entering the stern tube.

When the evaporator coils are located directly inside the refrigerated space the system is known as _____

a direct system.
a double evaporator system.
an indirect system.
a low pressure system.

The two valves shown on the left of this picture are called flat valves and give a high throughput for a small lift in height. They are mostly used for _____

a stop (zero flow) valve.
process stability, for a certain percentage in lift changes the throughput by the same percentage.
open - close regulation.
self correcting flow valve, by changing pressures in the system the throughput the same.

An abnormally hot suction line in a refrigerating plant may be due to _____

insufficient refrigerant.
too much oil in circulation.
high latent heat of evaporation.
too much refrigerant.

After a total black-out with an automatic power supply system, what is the correct sequence for restarting the essential pumps once the power is restored ?

Main sea water pump, jacket CW pump, piston CW pump, lub oil pump, injector CW pump.
Main lub oil pump, jacket CW pump, piston CW pump, injector CW pump, main sea water pump.
Jacket CW pump, piston CW pump, injector CW pump, lub oil pump, main sea water pump.
Injector CW pump, main sea water pump, jacket and piston CW pump.

The reason why two-stage starting air compressors are used in preference to single stage compression is that _____

the friction in a single stage compressor would be too high.
the power absorption by single stage compression would be too high.
the temperature developed by single stage compression would be too high.
the starting current of a single stage compressor would be too high.

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