Competency_4
What is the reason why steam pressure reduces its pressure while accomplishing work in the engine or turbine?
The steam expands in volume
The steam becomes superheated again
The steam volume diminishes
The steam becomes saturated again
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
First effect scale formation to be loosened
Decreased priming and lower salinity distillate
Increased heat levels throughout the entire unit
If the boiler fires are extinguished by the water contamination in the fuel oil, you should FIRST?
Reduce the load on the boiler
Secure the burner valves
Purge the boiler furnace
Secure the settler tank suctions
After changing out the fuel filters, the diesel engine fails to restart. What could be the probable cause?
Change in viscosity?
Air-bound fuel system
Low compression
Improper spark
After the installation of new impeller wearing rings by pressing them onto the pump impeller hub, it is advisable to?
Visually inspect the rings after about an hour of service
All of the above
Dynamically balance the shaft and impeller
Check the shaft and impeller assembly on centers to see if the ring surfaces are true
Which is the function of a boiler diffuser assembly?
Serves to mix the air evenly with the fuel
Adds heat to the fuel particle one
Shapes the fuel particles into a cone
Acts as a shield to prevent flare back
What would be the result if the fuel used for boiler burners has sediments?
Panting in the furnace
Clogged atomizer tips
Excessive white smoke
Sputtering of atomizers
Moisture in a refrigeration system will cause a _______.
High suction pressure.
Faulty expansion valve.
High suction temperature.
Low discharge temperature.
What will happen if the fuel injected too early in the injection cycle?
Smoky exhaust
Better fuel atomization
Lower exhaust temperature
Early detonation and loss of power
In a refrigeration system, how do you clean the oil filter?
Remove and clean with gas
Remove and soak in soap and dry by air blowing
Take out and blow with air
Pulling out and clean with chemical
At what pressure should a cylinder relief valve of an internal combustion engine be set to relieve?
Cylinder relief valves are no longer required for large low speed engines due to advancements in combustion engineering
Cylinder relief valves should only be adjusted by an authorized repair facility with the permission of the OCMI
The device should be set to relieve at a pressure not more than 40 percent in excess of the maximum firing pressure
The valves should be set to just stop relieving with the engine running at full speed
Which of the following determines the measured gap between the face of the burner atomizer tip nut and the diffuser plate?
Diffuser plate
Distance piece
Sprayer plate
Atomizer tip nut
In a mechanical compression refrigerating system, what is the main cause of a very low discharge pressure?
Insufficient refrigerant in the system
Excessive opening of expansion valve
Valve breakage inside the compressor
Air inclusion refrigerating system
The high pressure cut-out switch will stop the refrigeration compressor when there is?
Accumulation of refrigerant in the crankcase oil
A stoppage of condenser cooling water flow
Restricted suction filter
Lack of refrigerant
The working principle of an engine is the conversion of?
Mechanical into electrical energy
Chemical into heat energy
Electrical into mechanical energy
Heat into mechanical energy
If the exhaust oil is returned directly to the pump suction, what type of hydraulic circuit is the system?
Low pressure loop
Open loop
Closed loop
Live line loop
One of the three available centrifugal sea water service pumps is in operation with a sea water temperature of 50 deg fahrenheit. The cooling temperature of all systems supplied by this pump appear to be high. Therefore, which of the following is required?
After starting the second pump, secure the first pump and do nothing else with salt water service system
After starting the second pump, open the casing vent valve of the first pump, then secure the first pump
Start a second pump and place it on line, close the discharge valve on the original pump and watch for a rise in the discharge pressure
Only need to start a second pump and operate it in parallel
A recirculating, or bleed off line is installed on a centrifugal pump in order to?
Establish a back pressure at the labyrinth seal to eliminate leakage
Decrease the net positive suction head
Equalize pressure on both sides of the suction valve disc
Prevent the pump from overheating when operating at shutoff head
What does an unusual or new vibration in the hull or propeller shafting indicate?
High engine speed
Propeller unbalance
Overheated bearings
Clutch slippage
Which of the following statement is true if the lube oil temperature is allowed to become excessively high in the heaters?
The lubricant will carbonize and its lubricating ability will be reduced
Excessive temperature will increase oil viscosity that results to poor combustion
Excessive temperature will cause the fuel oil to crystallize resulting in pulsating fires
The fuel will ignite even it has not reached point of ignition
How can we quickly reduce high water level in a steaming boiler?
By the use of bottom blow valve
By the use of water column valve
By the use of safety valves
By the use of surface blow valve
Why are relief valves of fuel service pump for boiler burners installed?
To regulate the atomizer pressure
To protect the pump from high discharge pressure
To control oil pressure regulators
To supply constant fuel pressure to the burners
One of the major components of centrifugal pump is?
Gear
Impeller
Piston
Screw
Which of the following is the reason for installing settling tanks in the fuel oil system?
To heat fuel in correct temperature for atomization
To filter and purify fuel oil
To purge air in the system
To heat, allowing sediments and water to settle down
When an engine coupled with the large vibrational shocks that act on the shafts, there could be a permanent damage to the propeller shafts. Why?
Because of the tail shaft weight
Because of the intermediate shaft weight
Because of the propeller shaft weight
Because of the thrust shaft weight
The capacity of a rotary pump will decrease with an increase in the pump
Operating noise
Suction pressure
Discharge pressure
Rotor clearance
Which of the following methods is used to counter axial thrust in a single flow reaction turbine?
A dummy piston and cylinder at the turbine inlet end
Carbon packing
Labyrinth packing
Pressure equalizing holes in the individual rotor wheels
If an air compressor is used to supply air primarily to the combustion control system and other pneumatic controllers, the entire system is know as the?
Ships service system
Supply air system
Control air system
Forced draft air system
Which of the following components is directly connected to the propellers and lies mainly encased in the stern tube?
Stern tube seal
Thrust shaft
Intermediate shaft
Tail shaft
Strainer is commonly used in hydraulic system in order to?
Prevent solid particles from entering the pump.
Protect the directional control valve.
Prevent solid particles from entering the filter.
Protect the pump from fine soluble contaminants.
How is the pressure and temperature affected in a diesel engine cylinder during compression?
Pressure and temperature increase
Pressure decreases and temperature increases
Pressure and temperature decrease
Pressure increases and temperature decreases
Which of the following determines the measured gap between the face of the burner atomizer tip nut and the diffuser plate?
Diffuser plate
Distance piece
Sprayer plate
Atomizer tip nut
An important point of consideration when replacing a dry type intake filter on an air compressor is to?
Use the same wetting oil on the element as is used in the compressor lubrication system
Install a smaller size filter to allow for expansion of the element
Install only a filter consisting of a treated paper element
Select the proper size filter so that air flow is not restricted
Component of an engine used to increase scavenging air is called __________.
Scavenging valve
Scavenging flaps
Engine blower
Turbocharger
Increases in rotor clearance in a rotary pump will?
Decrease pump cavitation
Decrease reaction ring clearance
Decrease pump capacity
Increase discharge pressure
It is a form of energy which crosses the boundary of a system during a change of state produced by a difference of temperature between the system and its sorroundings.
Heat
Potential energy
Kinetic energy
First law of Thermodynamics
The capacity of a rotary pump, when operated at a constant speed, will decrease with an increase in the pump?
Discharge volume
Rotor clearances
Steeped speed
Suction pressure
The follow-up mechanism for any steering gear is to assure one rudder position for each corresponding position of the helm. Therefore, the follow-up mechanism should?
Maintain main pump variable stroke angle after command rudder angle has been achieved
Rapidly return the main pump variable stroke device to neutral stroke just as the rudder achieves command angle
Be gradually increasing main pump variable stroke device as rudder attains command angle
Be returning the main pump variable stroke device gradually to neutral stroke just as rudder is achieving command angle
The amount of supplied fuel oil on the boiler atomizer depends on the?
Atomizer holes
Boiler pressure
Steam pressure
Fuel pressure
What is the function of double-volute casing of a centrifugal pump?
Reduce hydraulic end thrust
Provide the effect of multi-staging
Reduce radial thrust to the impeller
Double the liquid velocity through the pump when compared to a single volute
Provision is to be made for ventilation of an enclosed diesel engine crankcase by means of a small ?
Fan to develop a slight suction not exceeding 1" of water
Breather or by means of a slight suction not exceeding 1" of water
Vent line attached to the upper most area of the crankcase near the center of the engine
Aperture not exceeding 1" in diameter
One advantage of a vacuum feed sight glass indicator used on cylinder lubricators over the discharge side liquid filled type sight glass is?
Adjustments are not required
Better visual metering adjustment
There are fewer moving parts
A lower grade of cylinder oil may be used
Gas turbine has operational flexibility. Which of the following is the reason?
Swift start up, no warm up or idling period is required.
High availability, underwritten by high reliability and rapid repair and/ or turbine change options.
Low noise and vibrations.
High power-to-weight and power-to-volume ratios.
Which of the listed turbocharger component increases air density and helps improve engine-operating efficiency?
Turbine blades
Impeller
Diffuser
Air cooler
Why diesel engine lubrication oil need more purification compare with the lubricating oil in a gas turbine?
Gas turbine lubricant is subject to far greater stress
Diesel engine lubricant might be contaminated with fuel
Gas turbine lubricant does not come into contact with the combustion process
Diesel engine lubricant might be contaminated with water
What is the use pf a steam control valves installed in the auxiliary exhaust line?
Control steam admission and maintain the proper steam spray pattern in the DC heater
Preheat the condensate before it enters the vent condenser
Regulate back pressure in the desuperheater line
Seal the vent condenser to prevent the escape of condensate
Fuel oil enters the main engine cylinder through?
Starting valve
Oil spill valve
Fuel oil injector
Plunger and barrel
When installing a new rotary pump, the suction piping should __________.
Be of same diameter as the pump suction connection
Be sloped to the pump
Be the next size smaller than the pump suction connection
Be at least one size larger than the pump suction connection
The function of the hydraulic telemotor transmitter used in an electro hydraulic steering gear system is to ____________.
Send hydraulic signals to the receiving unit
Prevent the control linkage from striking the stops when hard over
Automatically purge all entertained air from the system
Transmit the rubber angle to the bridge indicator
Which of the following purpose of a safety valve fitter in the cylinder cover of a diesel engine?
To release excessive gas pressure from the cylinder
To release gas from the cylinder by operating turning gear
To open in port so the engine cannot be started
To drain off water and condensate from the cylinder
The boiler feedwater control valve varies the relationship between steam and water flow during periods of?
Minimum boiler load
Overload operation Â
Load change Â
Steady boiler load
The most common problem encountered by turbo-chargers in a two-stroke engine is?
Surging
Merging
Purging
Charging
Which of the following will increase when fuel oils are heated?
Specific heat viscosity
Specific gravity
Volume
Which of the following will increase when fuel oils are heated?
Specific heat
Viscosity
Specific gravity
Volume
When operating under constant load, the superheated steam temperature may rise above normal if __________.
Excess air is too low
Feed water temperature is too high
Feed water temperature is too low
Excess air is too high
In a refrigeration system, the amount of refrigerant admitted to the evaporator is directly related to __________.
Condenser cooling water temperature
The solenoid valve differential pressure
The superheat of the refrigerant in the tail coil
All warding files the compressor discharge pressure
The heat gained per pound of refrigerant in the evaporator is know as the __________________.
Refrigerating effect
Specific heat of vaporization
Sensible heat
Latent heat of vaporization
The range of values around a setpoint of a measured variable where "no action" occurs in an automatic flow controller is called:
Deviation
Bias
Deadband
Error
In the Hydropore tank, what is the device installed to start/stop the pump?
Timer
Level Switch
Temperature Switch
Pressure Switch
Which of the following is a function of burner atomizing steam?
Impart swirling motion of the oil for efficient combustion
Maintain a constantly high fuel pressure
Maintain constant high fuel temperature
Prevent overheating of the atomizer
If the discharge valve is closed before the drive motor is stopped, which type of pump will most likely be damaged?
Gear pump
Reciprocating pump
Centrifugal pump
Turbine pump
How is power transferred from the main engine located deep inside the hull of a vessel to the propeller at the aft?
Via intermediate shaft
Via thrust shaft
Via tail shaft
Via intermediate and propeller shaft
In a large slow-speed propulsion diesel engine, the force applied to the piston is _______________.
Against the crosshead during the power and compression strokes
Against the crosshead during the compression stroke and away from the crosshead during the power stroke
Against the crosshead during power stroke and away from the crosshead during the compression stroke
Away from the crosshead during the power and compression strokes
Air leakage between the shaft and stuffing box packing in a centrifugal pump is prevented by?
Lantern rings between the packing rings
The stuffing box gland
A compressed packing gland
A liquid seal
Which of the following is used as moisture arrester and dryer in the refrigeration system?
Oil separator
Drain valve
Silica gel
Bimetallic thermostat control
An air-compressor can be unloaded at start up by?
Using an enlarged, permanently opened expansion space
Holding the discharge valve open
Relieving the intercooler pressure to the atmosphere
A pre-charged accumulator
Fuel leakage in high-pressure fuel pipe between the injection pumps and the fuel nozzle needs immediate repair because of _______________.
Distortion of the spray pattern
Clogging of the orifices
Serious fire hazard
High cost of fuel
Air compressor cylinder unloader enable the compressor to?
Reduce compressed air charge density
Start and come up to speed before air compression begins
Change speed according to overload demands
Vary their speed according to temperature
What part of na engine transmits the reciprocating motion of the piston to the driven unit in the form of rotary motion?
Propeller shaft
Fuel pump
Crankshaft
Tail shaft
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.
Temperature volume diagram
Pressure temperature diagram
Pressure volume diagram
Temperature entropy diagram
Which of the following would result if the temperature of the fuel to the burners is too low?
The boiler will produce dense white smoke
The clogging of fuel service strainers
The boiler will produce heavy black smoke
The fuel service pump will lose suction
Noise and vibration in a condensate pump would be caused by?
Running in the wrong direction
Bent shaft
Excessive speed
Worn wearing rings
An inadequate reciprocating bilge pump discharge is most often caused by?
Scarred cylinder walls
Clogged suction strainer
Clogged drain valves
Defective intake valves
On a medium pressure, differential piston, reciprocating air compressor, lubrication of the pistons/cylinders is usually accomplished _______________.
By the splash method
Gravity fed lubricators
Lube oil flow from the bearing lube oil system
With metering type cylinder lubricators
When turbine rotor shafts extend through the casing, an external source of sealing steam is used in conjunction with labyrinth packing to _____________.
Provide a constant flow to the gland leak off condenser
Seal the casing during periods of low casing pressure
Maintain the rotor journal journal temperature
Seal the casing during periods of high casing pressure
What result will be achieved in maintaining fuel oil temperature properly?
The elimination of valve wear
A decrease in cylinder blow-by
An increase in cylinder blow-by
Improved atomization
The rotary motion of a diesel engine crankshaft is obtained from the up and down motion of the piston via the?
Connecting rod or piston rod
Camshaft
Rocker arm
Reduction gears
The ash content of a fuel oil is significant to the operating engineer because ?
It is an indication of the amount of noncombustible material present in the oil
Indicates the quantity of energy released by burning a unit amount of fuel
Reflects the overall thermal efficiency of the fuel oil service systems
Is useful for determining proper atomization temperatures
How does fuel oil atomizers function in boilers?
By breaking fuel oil into a fire spray
By controlling the amount of air entering the furnace
By controlling the fuel temperature
By mixing fuel and air together
In a diesel engine, the fuel consumption is expressed in ?
Tons per day
Grams per horsepower per hour
Liters per horsepower per hour
Kiloliters per day
What is the possible cause of fuel oil accumulation in boiler casing is?
High atomizing steam pressures
Faulty return traps
Leaking fuel oil strainers
Dripping atomizers
Jacket water temperature in a closed cooling system of a diesel engine is normally controlled by?
The operation of the thermostatic valve
Varying the engine load to meet temperature requirements
Regulating the chromate level in the primary
Quick level of the fresh water expansion tank
How many fuel oil heaters are required for main engine operation?
The system shall be designed to permit series or parallel operation
Each heater shall have the capacity to supply the main engine at full power
At least two heaters of approximately equal size are to be installed
None of these choices
According to Regulations, a power driven auxiliary steering gear for a vessel capable of a 12 knot service speed, must be able to meet the rudder movement requirements at which of the minimum vessel speeds listed below?
6 knots
7 knots
12 knots
9 knots
As the pump speed increases, what will happen to NPSH (Net Positive Suction Head) ?
NPSH increases
NPSH should be half the original speed
NPSH remains the same
The action should take
In the water tube boiler, the fire in the furnace is located at the?
None of the choices
Outside the tubes
Inside and outside the tubes
Inside the tubes
Maximum rated horsepower of a diesel engine is attained?
  when the engine RPM is pulled down by overload
  at the speed of maximum torque
  at 50% of rated engine RPM
  at rated engine RPM
The net positive suction head of a boiler centrifugal feed pump should should be calculated over and above the ___________.
Speed of the imperller
Impeller ratio in the pump
Feedwater vapor pressure
Pump capacity in GPM
What is the heat exchanger used to heat the boiler feed water by means of waste gas as it passes from the boiler to the stack?
Oil heaters
Fresh water heater
Close condenser
Economizer
What is the most important rule for the safe operation of a boiler?
Clear the strainer
Clean the burner
Check for the quality of fire
Maintain the proper water level at all times
Which of the following is the purpose of the diffuser in a burner assembly?
To diffuse flame to all corners of the furnace
To shield the flame from incoming air blast while allowing mixing of fuel and air
To assist combustion in the incoming air
To break up fuel into a fine spray
You observed an efficiency drop caused by compressor fouling of the gas turbine, what is the most effective counter measure to carry out?
On-line washing
Off-line washing
Turbine washing
Compressor washing
Diesel engine jacket water is used in the fresh water distillation process as the ?
Coolant for the brine cooler
Means of heating the feedwater
Coolant for the distillate
Primary means of producing a vacuum within the distiller
A twin-screw, rotary, positive displacement pump is provided with timing gears. If it were possible to change the lead (pitch) of the screws, which of the following statements would represent the true effect on the pump characteristics?
The longer the lead, the lower the axial velocity
The shorter the lead, the higher the pressure potential
The shorter the lead, the higher the inlet pressure requirements
The longer the lead, the lower the flow rate
Centrifugal pumps, used to handle hot liquids, must have a minimum flow through them under all operating conditions. This flow serves to?
Maintain hydraulic differential in the pump impeller passages
Prevent overheating and vapour bound conditions
Keep the shaft glands cool
Maintain the net positive suction head of the pump
What type of pump is used in the steering gear of modern ship?
Centrifugal
Gear
Vane
Reciprocating
In case Engine room is unmanned and Diesel Engine is running, when the temperature of cooling water outlet is one degree above the limit in long period of time. What is the next immediate better thing to do?
Check the setting of the RPM indicator
Check the setting of temperature controller
Check the setting of lube oil controller
Check the cleanliness of fresh water cooler
The dehydrator of a refrigeration system is located?
Before expansion valve
After oil separator
After evaporator
Before liquid receiver
An incinerator is a waste disposal unit that will burn?
Liquid material
Gases
Solid material and all types of liquid waste
Solid material
An incinerator is a waste disposal unit that will burn?
Liquid material
Gases
Solid material and all types of liquid waste
Solid material
What is a practical way of checking for excessive fuel injection in one cylinder of an operating diesel engine?
Check the cylinder exhaust for white smoke
Feel the high pressure fuel line
Isolate each cylinder and inspect the injector
Check the cylinder exhaust temperature frequently
In order to move the rudder, what must be created by steering gear?
Friction
Load
Torque
Force
Gland sealing steam is used during steam turbine operation to prevent the loss of _____________.
Temperature
Vacuum
Oil
Air
If the control pressure for an automatic combustion control system is lost during maneuvering, you should ____________.
Blowdown the air receiver
Secure the boilers
Attempt to restart air compressor
Switch to manual control
What is the means of removing the heat of condensation from the refrigerant in a normal refrigerating cycle?
Condensing the refrigerant in the system condenser
Passing the refrigerant in the heat exchanger of the suction side of the compressor
Passing refrigerant to freezing point
Passing the refrigerant to expansion valves
A hydraulic actuator is a device that uses hydraulic energy coming from a hydraulic pump and produces linear mechanical power. What component of the device that produces linear mechanical power?
Hydraulic pump
Hydraulic motor
Hydraulic cylinder
Hydraulic clutch
KPa is equivalent to?
2,250.2 bars
43.52 psi
7.5 mm of Hg
3 in of Hg
The pressure developed in the high pressure cylinder of a reciprocating air compressor, in order to assure an output near the end of its compression stroke, is?
Constant throughout the discharge period
Above the line discharge pressure
Below the line discharge pressure
The same as the line discharge pressure
The demisters installed in a flash-type evaporator serve to?
Deaerate the first effect distillate
Filter the condenses flash vapors
Deaerate the first and second effect distillate
Remove small water droplets entrained in the flashed vapor
Stern tube is used to?
Support and seal the propeller shaft
Protect the engine from its axial thrust
Reduce vibration of engine
Transmit the power from main engine to propeller
The dimension of the thinnest hydrodynamic film developed within a full journal bearing, when all other factors remain constant, depends upon the ?
Interfacial tension of the lubricant
Fluidity of the lubricant
Dielectric strength of the lubricant
Pour point of the lubricant
Main engine lube oil sump tank is located?
At the bottom of the engine
At the same level as the main bearing
Above the engine
Next to the engine
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 discharge piping, with all other factors remaining the same
Width of the impeller
Diameter of the suction piping, with all other factors remaining the same
Diameter of the impeller
Air leaking into a flash type distilling plant could occur through __________________.
Salinometer, valve steam, and gage glass packing
Gasketed joints, cooling tube, and valve stem
Gasketed joints, valve stem, and gage glass packing
Gasketed joints, cooling tubes, and gage glass packing
The operation of a thermostatic steam trap depends upon the ?
Difference in movement of two dissimilar bimetallic strips not fastened together
Fact that hot water under pressure tends to flash into steam when its vapor pressure is rapidly reduced
Change in the amount of vapor produced within an enclosed chamber
Action of a float within a chamber
One method of constructing large marine diesel engines and reducing the total engine frame is through ?
Case hardening integral components
Welding plates to form sections for assembly
Casting interlocking components
Forging integral components
What is the importance of the control box of a differential gear system in steering gear system?
It compares the bridge signal to the actual rudder angle through the follow up gear
It controls the mix-way-valve
In controls the flow of hydraulic oil to the rams
It connects to the transmitter from the remote station to the receiver at the steering gear room
How is dissolved oxygen in boiler feed water minimized?
Surface blow down
Phosphate treatment
Bottom blow down
Maintain high feed water temperature
Why are burner registers to be left open for a few minutes when securing burners ?
To cool the uptakes
To stop steam generation
To cool the furnace
To purge the furnace
What need to be done in order to maintain the gas turbine sustainable power output?
External grain washing
Compressor washing
Internal grain washing
Turbine washing
Why should a boiler furnace be purged before the burner is lit off?
To clear the windbox of any explosive gases
To ensure proper fuel to air ratio
To clear the furnace of any explosive gases
To control air pressure in the wind box
When an engine coupled with the large vibrational shocks that act on the shaft, and there could permanent damage to the propeller shaft and Why?
Due to thrust shaft weight
Due to tail shaft weight
Due to propeller shaft weight
Due to intermediate shaft weight
What will happen if the needle valve in a fuel injection nozzle sticks open ?
The nozzle will overheat
Injection lag will be increased
Fuel will leak into the nozzle drain line
No fuel will be delivered through the nozzle
What part of an engine has the function of measuring the speed and changing the fuel control __________________?
Injector
Generator
Governor
Indicator
Boiler safety valves are set not to go above maximum operating pressure of higher than ?
0.2
0.1
0.15
0.05
In order to recognize the amount of anchor chain paid out, specific potions of the chain are color coded and wrapped with wire. The first shot of chain is painted ?
Red on the detachable link and red on each link to either side of the detachable link
White on the detachable link and red on each link to either side of the detachable link
White on the detachable link and white on each link to either side of the detachable link
Red on the detachable link and white on each link to either side of the detachable link
Purging air from a hydraulic oil system is necessary when ?
Adding small amount of oil to the system
System has been drained and filled with new oil
System has been idle for a long period
System has been overheated
Which turbocharger component increases air density and helps improve engine-operating efficiency?
Exhaust diffuser
Impeller
After cooler
Compressor
What is the effect if fuel oil tanks of a vessel is half full ?
Severe hogging
Severe sagging
Free surface effect
Serious loss of reserve bouyancy
Some engines are using auxiliary electrically driven blowers, which is continuously running during maneuvering, and automatically cut-off, if the scavenge air pressure reaches ________ load.
50%
80%
60%
25%
If the flow of water from the centrifugal pump is allowed to be stopped by closing the discharge valve while the pump continues to run for an extended period, which of the following will occur?
The water pressure will rise above shut off head
The wearing ring will become excessively worn
Liquid in the pump will overheat
The water pressure will decrease to shut off the head
The camshaft drive is designed to maintain proper camshaft speed relative to crankshaft speed. In maintaining this relationship, the camshaft drive causes the camshaft to rotate at ?
One-fourth times crankshaft speed in a four-stroke cycle diesel engine
Two times crankshaft speed in a two-stroke cycle diesel engine
One-half crankshaft speed in a two-stroke cycle diesel engine
Crankshaft speed in a two-stroke cycle diesel engine
It refers to an internal combustion engine practice, where there is a necessity of heating the oil, to ensure easy flow and good atomization _______________.
Tracing steam
Pre-heating
Re-circulating
Pilot injection
The purpose of the six-way valve used in an electro-hydraulic steering system is to _____________.
Ensure positive contact between the Rapson slide and the rudder post
Redirect hydraulic fluid flow when changing over pumps
Take the pump off stroke when desired rudder angle is attained
Parallel rudder motion to the steering wheel
Prior to departure what preparations are required regarding pistons and cylinder liners of a diesel engine ?
Preheat cylinders and pistons turn engine turn cylinder lubricators
Open starting air start booster pump start stern tube pump
Close safety valve put out turning gear open air bottles
Open indicator cocks close safety valve turn lubricators
Which part of a diesel engine that fuel is admitted into the cylinder combustion chamber ?
Intake valves
Exhaust ports
Injector nozzles
Carburetor
Schedule of soot blowing for economizers is done for at least ?
Three times a month
Three times in a year
Three times a day
Three times a week
What part of a refrigeration system reduces the pressure of a liquid refrigerant?
Liquid receiver
Expansion valve
Tube condenser
Reefer compressor
Which of the following characteristics that determines the temperature to which fuel must be heated for proper atomization is ?
Flash point
Specific gravity
Pour point
Viscosity
When should be a boiler water sample be taken for testing>
After the boiler has been blown down
From the highest point in the feed system
Before the boiler has been blown down or chemicals added
When the boiler has been refilled with make-up
What is the primary function of a fuel delivery check valve assembly ?
To control fuel quantity entering the pump body
To deliver proper fuel quantity to the injection nozzle
To control fuel pressure delivered to the combustion chamber
To provide rapid fuel injection cut-off
Which combination of the main shaft segments listed below that are located furthest from the main engine are connected by inboard stern tube shaft coupliong?
Thrust shaft and stern tube shaft
Stern tube shaft and tail shaft
Line shaft and thrust shaft
Line shaft and stern tube shaft
The cooling effect in a refrigeration system is produced by ____________.
Increasing the pressure of the refrigerant.
Pressure changes to the refrigerant.
Lowering the pressure of the refrigerant.
Boiling the refrigerant.
Which type of pump is used in steering gear of modern ships?
Reciprocating
Vane
Centrifugal
Gear
Carbonization in the surface of the fuel oil heater will reduce the heating capacity because ?
Radiational heat is reduced
Fluid film covers the surfaces reducing the heat transfer
Loss of heat transfer
Relative velocities of the flow of liquid decrease causing corresponding
Scavenging trunks are more prone to fire because they are ?
Accumulating oily substance
Located below the cyclinder
Recipient of fresh air
Always over pressure
If condensate is accumulated in the steam side of a fuel oil heater, it could result in ?
Corrosion
Scale accumulation
Overheating
Immediate oil contamination of the condensate
Some engines are using auxiliary electrically driven blowers which is continuously running during maneuvering and automatically cut-off if the scavenge air pressure reaches __________ load.
50%
60%
80%
25%
A mooring winch should be equipped with mechanical brakes capable of holding _____________?
The full breaking strength of the mooring line
50% over the working tension of the mooring line
The maximum expected tension of the mooring line
Half the breaking strength of the mooring line
The set point pressure at which the boiler safety valve is to lift to ?
Boiler full capacity pressure
Designed pressure
Maximum steam drum pressure
Boiler overload capacity
The boiler water having a pH reading of 7.0 is said to be ?
Neutral
Alkaline
Acidic
Basic
What is the characteristic of a one ton air conditioning system?
Its cooling power equals melting 907 kg (2000 lbs) of ice per day.
It forces 907 kg (2000 lbs) of air per hour through the evaporator coils
It circulates 907 kg (2000 lbs) of refrigerant through the system per day
The system contains 907 kg (2000 lbs) of rerigerant
The correct radial clearances between the rotor and the casing in propulsion turbine are maintained by the turbine __________.
Diaphragms
Journal bearings
Interstage packing
Thrust bearing
Why diesel engine lubricating oil need more purification compared with the lubricating oil in a gas turbine?
Gas turbine lubricant is subject to far greater stress.
Gas turbine lubricant does not come into contact with the combustion process.
Diesel engine lubricant might be contaminated with water.
Diesel engine lubricant might be contaminated with fuel.
To what purpose why is strainer install on hydraulic system ?
To protect the pump from fine soluble contaminants.
To prevent solid particles from entering the pump.
To protect the directional control valves.
To prevent solid particles from entering the filter.
A boiler fuel burner that is equipped with a variable capacity pressure atomizing system functions to _________________.
Maintain smokeless fuel oil combustion
Provide constant fuel pressure
Maintain constant fuel temperature
Provide wide range of combustion
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