Maintenance Procedures. Test 2 – Online Maritime Tests

When opening a Plate Cooler for cleaning, how should the bolts be removed?

One by one.
Fully slacken and remove top ones first, then middle, then bottom.
Casually slacken all bolts.
Fully slacken and remove middle bolts first, then top, then bottom.

The plate heat exchanger is separated for cleaning. What will You do if the plates are thick with scale or other organic material?

Use high-pressure cleaner with abrasives.
Use wire-brush, metal scrapers etc. for cleaning of plates.
Change the plates.
Put the plates in water with qualified cleaning chemicals, and use soft brush, or high pressure cleaner with care.

The water cooling space on the turbocharger is damaged and you have no spares. The cooling water must be closed. Which steps would you take to ensure least possible damage?

Dismantle the rotor and assemble the sealing plate.
Cool the turbocharger by means of air.
Run the engine at a lower speed.
Make no modifications, but tell the duty engineer to pay special attention for abnormalities.

Some engine manufacturers recommend that washing of the compressor side is not carried out. Is this due to:

The nozzle ring becoming corroded.
Greasy sludge from the compressor sticking between the fins in the air coolers, necessitating extra cleaning of these.
Large volumes of water being carried over into the cylinders of the engine.
The thermal shock exhibited by the vanes.

Fluctuation of high temperatures under flame impingement, makes the surface of the firebrick breaking away in layers. What is the correct engineer term for this?

Shrinking.
Slopping.
Slagging.
Spalling.

If inspection or repair of the boiler is due, the plant has to be shut down, and the boiler emptied for water. If time is available, which of the following procedures are correct?

The boiler be allowed to cool down by its own after shut down. Then pump the water out.
The boiler be blown down to sea immediately after shut down.
The feed water regulator to be bypassed and the boiler topped up with cold feed water immediately after shut down.
The safety valve easing gear be operated and all the pressure released immediately after shut down.

After cleaning and back in service, You observe that the heat transfer is bad. What is the first thing to do?

Check for proper air vent of the exchanger.
Increase the pressure.
Dismantle the exchanger again.
Decrease the pressure.

The meaning of lapping a valve and valve seat is:

Machining the valve in a lathe machine.
Adjust the overlapping of the inlet and exhaust valves.
Repair by welding.
Grind the valve against the valve seat to obtain a uniform sealing surface.

What will you do if the heat transfer capacity is dropping, and we know that flow and heat energy corresponds to the specifications?

Use the 'cleaning in place' arrangement to open the heat exchanger for visual inspection and manual cleaning.
Try to increase the flow.
Add some more plates to the exchanger.
Increase the pressure.

Review Answers