Auxiliary Machinery. Test 5 – Online Maritime Tests

Feed check valves for main and auxilliary purposes are normally of the double shut off type, as shown in the diagram. What is the main function of the non-return valve?

To allow fine tuning of feed water flow to the boiler.
To increase the workload for staff when overhauling the boiler.
To allow overhaul of the screw down valve when the non-return valve is shut and the boiler is steaming.
To prevent the steam and water in the boiler from discharging out by the feed line, if a feed line fracture or a joint in the line blows.

Which items are important to get an optimal separation?

Low temperature and flow.
Max flow and high temperature.
Max flow and min. pressure.
Correct flow, pressure and temperature. ( Viscosity)

The boiler have been shut down completely for inspection and repair. You have finished work and are going to start firing the boiler. What is the correct procedure for heating a boiler from cold?

Start with intermittent firing, using small firing periods and long intervals gradually building up to longer firing periods and shorter intervals.
Start the firing on minimum rate and continuously fire until boiler is up to pressure.
Start the firing on minimum rate and alternate with maximum rate continuously firing until the boiler is up to pressure.
Start the firing on maximum rate and raise the pressure in as short a period as possible, to save energy.

When an air compressor is going to be started it is important that the compressor is started with the 'blow off' valves open. Why?

To be sure that all pressure valves in the HP line to the starting bottle are open.
To ensure that we do not have any water assembly in the cylinders when the compressor start.
To ensure that the electric motor will not have a too low torque during start.
To ensure that the compressor does not have any back pressure due to a leak suction valve in stage one.

After complete shut down of the steam plant, the boiler have been heated in accordance to correct starting up procedure, and is now firing at working pressure. You are going to open the main steam valve to the system. What will be the correct procedure for this operation?

Open as fast as possible to get rid of water assembly in the piping system.
Open as fast as possible to heat the piping system.
Open steam valve very slowly, considering system expansion.
Don't open the main valve before you have top pressure on the boiler.

What is the meaning of the term Clarification?

Separation of two insoluble liquids with different densities, and at the same time, removing of solids.
Separation in a single system.
Separation of solid contaminants from a liquid.
Separation of water.

How do You want to operate the purifier to obtain the best separation result?

By high flow and high temperature.
By high flow and low temperature.
Flow and temperature has no influence of the result.
Separation with correct temperature and low flow rate.

Classification societies require that when initially fitted to a boiler, safety valves must be subjected to a test of accumulation of pressure. Is this to:

Ensure the maximum firing rate can keep the pressure above normal working pressure.
See how high the boiler pressure will go before the safety valve operates.
See at what pressure the safety valve will reset.
Ensure the valves are of the correct discharge capacity for the boiler.

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