competence 4

100問 • 1年前

Leodegario Almaden jr.

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問題一覧

Air leaking into a flash type distilling plant could occur through

gasketed joints, valve stem, and gage glass packing

A salinity indicating system functions on the basic principle of measuring the

electrical conductivity of water

To keep the movement of the rudder closely in step with the steering wheel, which of the devices listed, when used on an electro-hydraulic steering gear ?

The follow-up gear

The capacity of a rotary pump, when operated at a constant speed, will decrease with an increase in the pump?

rotor clearance

Fluctuations in the pressure and temperature of the steam supplied to the first-effect of a low pressure submerged tube distilling plant will cause

pressure and temperature fluctuations in the entire unit

The temperature of the refrigerant in the evaporator coil defends mostly upon the the

Refrigerant pressure in the evaporator

Which combination of the main shaft segments listed below, that are located furthest from the main engine are connected by the inboard stern tube shaft coupling?

Line shaft and stern tube shaft

A distorted spray pattern from a fuel injector can cause a diesel engine to have ?

less power output

Movement of the pump control rack in a fuel injection system having individual plunger type pumps ?

changes the lenght of the pump stroke

What is the importance of the control box of a differential gear system in a steering gear system?

it compares the bridge signal to the actual rudder angle through the follow up gear

Which of the following component is the primary shaft emerging out of the engine. It directly receives the rotational motion from the crankshaft and rotates at the maximum velocity in high-speed engiens

Thrust shaft

The firing rate of boiler using steam atomization is indicated by the ?

fuel oil supply pressure

Which of the following cases listed below should soot blowing be applied to avoid soot fires ?

Prior to an increase in power

What is the use of a steam control valves installed in the auxiliary exhaust line?

Control steam admission and maintain the proper steam spray pattern in the DC heater

If the flow of wter from the centrifugal pump is allowed to be stopped by closing the discharge valve while the pump continues to run for and extended period, which of the following will occur?

liquid in the pump will overheat

What is the characteristic of a one ton air conditioning system?

Its cooling power equals melting 907 kg. (2000 lbs) of ice per day

The dehydrator of a refrigerator system is located?

before expansion valve

Cylinder oil is used for ?

2-stroke engine

The average pressure exerted on a piston during each power stroke is termed

mean effective pressure

Strainer is commonly used in hydraulic system in order to ?

prevent solid particles from entering the pump

The working principle of an engine is the conversion of ?

heat into mechanical energy

The function of a centrifugal pump double volute casing is to ?

reduce radial thrust on the impeller

Distortion of the spray pattern of a nozzle or injector maybe indicated by alan ?

cooling water temperature rise

What precaution should be oberved to prevent damage of the service pump when warming up the fuel system to the boiler is to?

close the recirculating valve when atomizing temperature is reached

Which of the following is the primary purpose of heaters in a pressurized fuel oil system?

improve the flash point of the fuel

Which of the following would result if the temperature of the fuel to the burners is too low?

The boiler will produce heavy black smoke

Prior to starting, the purpose of turning over a main propulsion diesel engine with the cylinder test cocks open, is to ?

remove condensation and other liquids from the cylinders

If the fixed orifice in the evaporator steam supply line were to be removed, the steam pressure reducing valve located upstream would

be unable to maintain steam flow unless the proper range spring were to be installed

What action would you take to perform the most important rule for the safe operation of a boiler ?

maintain the proper water level at all times

How do you control freshwater heating temperature in the evaporator side of a Fresh Water Generator ?

Regulate outlet vavle

Inspection of a low pressure gear pump for cavitation will usually be indicated by a wear pattern?

along the inlet side of the housing

Integral water jacket liners use O-rings near the bottom of the liner. These O-rings serve to ?

prevent the escape of lubricating oil from the crankcase

What part of the boiler provides water circulation to the waterwall tubes?

Downcomers

One of the routine task onboard maintenance for gas turbine is manly of daily visual checks of the running engine. What are you going to execute after a fix number of operating hours to remove any salt deposits on the compressor?

Internal water wash

What causes carbon deposits in the fuel heater ?

high fuel temperature

What is the cause of excessively low air pressure in the intercooler of a reciprocating air compressor ?

leaky discharge valves on the LP cylinder

While ovehauling a jerk-type pump and the pump plunger must be replaced. What other part must also be replaced ?

Pump barrel

During injection , the cam nose of the camshaft will push up the plunger of the pump, forcing the fuel to the ?

fuel injector

Increasing the speed of a centrifugal pump will result in an increase in the pump capacity. Another means of increasing the total head pressure of a centrifugal pump is to increase the ?

diameter of the impeller

Which of the following component is the primary shaft emerging out of the engine? It directly receives the rotational motion from the crankshaft and rotates at the maximum velocity in high speed engines

thrust shaft

The greatest decrease in the temperature of a refrigerant is at the

expansion valve

How does a quick closing valve operate?

the valve bridge is collapse remotely allowing the valve to close

If the boiler fires are extinguished by water contamination in the fuel oil, you should FIRST?

secure the burner valves

How is viscosity of fuel in the atomizer can be reduced?

increasing the fuel oil heater steam supply

In an engine operation what is the effect called that describes the unstable operation of the governor that will not maintain a steady state condition ?

Hunting

The possible cause why lube oil pumps fail to build up discharge pressuer could be that the ?

suction valve is closed

Which of the following statement is correct relative to distillation plant operation ?

Distillation is the process of boiling seawater to produce vapor which is condensed into fresh water

How many fuel oil heaters are required for main engine operation ?

at least two heaters of approximately equal size are to be installed

Some engines are using auxiliary electrically driven blowers which is continously running during maneuvering and automatically cut-off if the scavenge air pressure reaches load

50%

What type of pump is used in the steering gear of modern ship ?

Vane

What is the possible cause of fuel oil accumulation in boiler casing is ?

dripping atomizers

Gas turbine uses a cycle that includes intake, compression, expansion and exhaust. Which of the following are you going to use to best explain the complete cycle

Pressure volume diagram

Which of the following determines the measured gap between the face of the burner atomizer tip nut and the diffuser plate

Distance piece

Most of the fuel injection pumps will then closed after injection because they are fitted with a ?

Spring loaded discharge check valve

Why is thin tipping design procedure is used in modern reaction turbines ?

reduce tip leakage

In a refrigeration system, the amount of superheat abosorbed by the refrigerant is adjusted at the

expansion valve

If turbine rotor shaft extend through the casing, what external source of sealing steam is used in conjuction with labrynith packing?

seal the casing during periods of low casing pressure

Labyrinth seals used to reduce leakage around a turbine shaft are constructed of

machine packing strips or fins

Visual inspection of a fuel injector valve, removed during overhaul, shows heat discoloration of the lower end of the valve. This is an indication of

valve leakage

An internally mixed steam atomizer requires which of the following compared to a return flow oil burner system?

Less excess air

What is the reason why fuel is heated before atomizing is to ?

decrease its viscosity

Which of the listed condition is responsible for causing the gland leak off steam from a propulsion turbine to pass through the gland exhaust condenser?

The use of a gland exhauster fan

Parts of the pump used to maintain the alignment of the pump are ?

bearings

A squeaking sound occurring from within an operating reciprocating air compressor is an indication of ?

tight compressor bearings

The function of seal cages, or lantern rings installed in the centrifugal pump stuffing boxes, is to

distribure the sealing liquid withing the stuffing box

An oil mist detector is used to detect an oil mist formation in the diesel engine crankcase. Which of the following causes oil mist formation ?

overheating of oil

The bore of a diesel engine describes the ?

ÀÀ diameter of the cylinder

How is constant steam pressure maintained?

By controlling the amount of heat supplied to the boiler

How will you know the flirting rate of boiler steam atomization indicated ?

By the fuel oil pressure

Which of the following is the result of excessively high fuel oil temperature?

Fouling of the heaters

Which equipment must be tested NOT more than 12 hours prior to getting underway from port when the voyage is to be of 48 hours or greater duration?

Steering gear

In the boiler as combustion control system, when the demand for steam is increased

air supply increases before fuel supply increases

The purpose of the diffuser in a boiler burner assembly is to

allow some mixing of fuel and air

What is the purpose of the dehydrator in refrigeration

Remove refrigerant moisture

Main component of the engine to regulate speed is the ?

governor

Movement of the pump control rack in a fuel injection system having individual plunger type pumps

changes teh length of the pump stroke

Most fuel injection nozzles are opened by?

fuel oil pressure

One of the routine tasks onboard maintenance for Gas Turbine is mainly of daily visual checks of the running engines. What are you going to execute after a fix numver of operating hours to remove any salt deposits on the compressor?

Internal water wash

Boiler safety valves are set not to go above maximum operating pressure of higher than ?

0.1

Why should hydraulic cranes by properly warmed-up before they are used?

Hydraulic fluid must be at the proper viscosity

In a main propulsion turbine installation, the condensate pump initially discharges toe the

air ejector condenser

If a reciprocating air compressor has a knock occuring in frequency with its operating RPM, the cause is probably

misalignment or worn main bearings

The range of values around a set point of measured variable where "no action" occurs an automatic flow controller is called:

Deadband

Passages are drilled at the diesel engine crankshaft in order to provide lubricating iol in the

piston rod bearings

If you hear a crackling sound coming from a salt water centrifugal pump casing, the most probable cause of the noise would be?

excessive suction lift

The capacity of a rotary pump, delivering a constant viscosity fluid, will decrease when the discharge pressure in increased, due to?

increased slippage

The measure of the amount of salt present in water is called?

Salinity Specific Gravity

Which of the following statement is correct when a piston is said to be at top dead center?

nearest to the cylinder head

The purpose of the six-way valve used in an electro-hydraulic steering system is to,

redirect hydraulic fluid flow when changing over pumps

Main engine lube oil sump tank is located ?

at the bottom of the engine

What is the most important rule for the safe operation of a boiler?

Maintain the proper water level at all times

When turbine rotor shafts extend through the casing, an external source of sealing steam is used in conjuction with labyrinth packing to

seal the casing during periods of low casing pressure

Why diesel engine lubricating oil need more purification compare with the lubricating oil in a gas turbine

gas turbine lubricant does not come into cantact with the combustion process

Which of the following is the reason for installing settling tanks in the fuel oil system

To heat, allowing sediments and water to settle down

Why is it necessary to transfer fuel oil to the setlling tanks ?

allow the sediments and water to settle

Part of centrifugal disc purifier use to hold discs in place and directs the flow of dirty liquid to the bottom then the discs as the oil flow upward is called

distributor

Which of the items listed below is normally describe a ventilating fan?

Axial flow

Which of the following terms is used to identify the pressure of the liquid ?

Suction head

If you were operating a centrifugal water services pumo with worn wearing rings, the

pump would develop insufficient flow

100

Irregular feeding or suring of the feedwater supply to a low pressure distilling plant may be distributed to

A dirty strainer in the saltwater feed pump suction line

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