Which of the following problems occurring in a hydraulic system could cause the use of an oil having a viscosity lower than specified?
Increased power consumption
Seal deterioration
Fast response and hunting
Oil film breakdown
The portion of a hydraulic hose that determines its overall strength, is the_________.
braided inner layer(s)
inner tube
outer cover
outer armor
The pour point of lubricating oils is affected the most by which of the following?
Extensive centrifuging
Wax content
Water content
Acid content
The neutralization number of lube oil used in the machinery has exceeded its permissible range, therefore, it will be necessary to ______.
renew the entire oil supply
add make-up oil
purify the oil
operate the machinery at reduced power
An organic solid lubricant, such as graphite, is suitable as an oil additive when used in_______________.
machinery bearings subjected to high temperatures
antifriction bearings on general service pumps
bearings subject to fluctuating loads
line shaft bearings
A filter used in a multi-operation hydraulic system would most likely be located______.
between the pump and the directional control valves
at the pump suction
between the control valves and the actuators
in the actuator return lines
What is the harmful effect of sulfur in a fuel?
It forms a corrosive acid when mixed with water or water vapor.
It causes excessive smoking and soot at low firing rates.
It doesn't readily burn when combined with oxygen.
It clogs fuel oil strainers more often
Additives commonly found in turbine lubricating oil includes,______________.
antifoaming agents, oxidation inhibitors, and extreme pressure additives
corosive agents, oxidation inhibitors, and extreme pressure additives
corosive agents, oxidation inhibitors, and oxidation inhibitor
corosive agents, anti-foaming, and extreme pressure additives
The ash content of a fuel oil is significant to the operating engineer because it_____.
is an indication of the amount of noncombustble material present in the oil
indicates the quanity of energy released by burning a unit amount of fuel
is useful for determining proper atomization temperatures
reflects the overall thermal efficiency of the fuel oil service systems
Dirt should not be allowed to contaminate a grease lubricant because the_______.
dirt is very abrasive when mixed with grease
bearings will leak oil excessively
dirt will cause corrosion of bearing
grease will become inflammable
Most fuel injection nozzles are opened by ______________.
fuel oil pressure
a cam operated follower
a spring-loaded pressure plate
timing gears keyed to the crankshaft
Proper atomization of fuel in diesel engine combustion chambers will _____________.
improve combustion
affect the injection pressure
reduce compression pressure
decrease power output
Differential needle valves used in fuel injectors are directly closed by _____________.
spring force
cam action
firing pressure
Which these can seriously damage fuel injection equipment caused by poor combustion and leads to excessive cylinder liner wear?
Water
Carbon
Viscosity
Density
Fuel injectors used in heavy fuel oil systems are usually provided with cooling to reduce _________.
carbon accumulation on the nozzles
cold corrosion of the nozzles
fuel viscosity for better atomization
fuel detonation in the cylinders
How should the fire main outlet valves, or hydrants be installed?
Pointing downward or horizontal to prevent kinking of the fire hose
In screened enclosures in all passageways
Where they are protected from weather
In a protected location to prevent cargo damage
An incorrect spray pattern produced by a diesel engine fuel injection nozzle can be directly caused by ____________.
overcooling of the nozzle
incorrect fuel rack setting
low firing pressure
excessive lube oil temperature
Fuel is admitted to a diesel engine cylinder through the _______________.
injector nozzles
intake valves
carburetor
exhaust ports
Fuel consumption is usually measured by a flow meter with a unit of __________.
kg/h
m°/s
m/c
tons/hr
What kind of lubrication wherein the contact surfaces are completely separated by an oil film?
Hydrodynamic
Mixed lubrication
Boundary lubrication
Forced lubrication
Maintaining the proper fuel oil temperature will result in _____________.
improved atomization
the elimination of valve wear
a decrease in cylinder blow-by
an increase in cylinder blow-by
A vessel has been equipped with an oil lubricated stern bearing and is undergoing a routine drydocking. Which of the following inspections should be made when the tail-shaft has been drawn?
The overall condition of the bearing surface should be examined
The shaft liner should be inspected for cracks and tested to insure a tight fit
The stern tube should be tested for cracks with dye penetrant
All of these choices
What is the main advantage of unit injectors over other fuel injection system?
The lack of high pressure fuel lines
Their relatively low injection pressures
Reduced wear of spray orifices
The lessened chance of fuel leaks into the engine sump
What is the purpose of an accumulator in a hydraulic system?
To store potential energy in the form of hydraulic fluid under pressure in the system
To collect any dirt in the system
To collect fluid from any small leak
To preheat the fluid during cold weather
Fuel oil discharged to the diesel engine cylinder is atomized at the _____________.
injector nozzle tip
turbocharger
fuel oil pump
Which of the following fuel oil characteristic is being used in the calculation / computations of quantity?
Flash point
On purifiers, as a rule of thumb, the time interval set between automatic de-sludging of 180 cst heavy fuel oil should be .............. ?
2 to 3 hours
1 to 2 hours
4 to 6 hours
6 to 8 hours
A segregated ballast system is a system where ___________.
ballast and cargo tanks are separated by cofferdams
all ballast is processed through the oily water separator
ballast is taken on and discharged through a separate main deck riser
all ballast lines, tanks and pumps are independent of those used for oil
In the diesel cycle, at what stage of the compression stroke is fuel injected inside the cylinder?
Before the end
At the beginning
At the end
After the end
How are hydraulic valve lash adjusters on diesel engine rocker arm assemblies lubricated?
By forced lube oil supply
By sealed self-lubricators
By metered hydraulic oil supply
By cup-fed grease
On a gear pump, what is the usual method of reducing the delivery pressure?
By adjusting the internal spring loaded pressure relief valve.
By throttling the suction valve.
By throttling the discharge valve.
By fitting an orifice in the discharge line.
When taking over the engine room watch, what should you check concerning the operational lubricating oil purifier ?
Check whether throughput is minimum, check the overflow pipe, check whether the alarm is activated
Check whether throughput is on maximum, check the water seal, check the overflow/water flow off pipe, check inlet temperature and back pressure.
Check the setting of the timers, check the inlet temperature, the back pressure, the bearing temperatures.
Check the Ferodo coupling, the bearing temperatures, the inlet temperature and the back pressure.
Fuel injection systems meter fuel, atomize fuel and ____________.
inject fuel at the proper time
create turbulence in the combustion chamber
aid in completing cylinder scavenging
minimize fuel penetration into the cylinder
The lubricating oil on the exhaust side of the turbine blower gets dirty after only a few hours in service. What can the reason be ?
Labyrinth seal leaking exhaust gas into the oil.
Damaged or worn turbine side bearing.
The wrong type of oil used.
Cooling water leak into oil space..
For a continous operation of diesel engine, why is it that the use of a duplex filter unit would be the best arrangement?
Changing filter elements would not interrupt engine operation
Filtering occurs twice in each pass of oil through the system
Clogging will not occur
Dropping pressure is half of that through a single filter unit
Which characteristic of fuel oil is the most significant when determining the temperature to which the fuel oil must be heated for proper atomization?
viscosity
flashpoint
pour point
specific gravity
If a bilge pump is able to develop vacuum, but is unable to sufficiently pump out the bilges, you would check for all of the following EXCEPT _____.
the circuit breaker
for leaks in the suction piping
relief valve is not properly seated
the suction strainer
Which type of pump would be most suitable for pumping large quantities such as oil cargoes ?
Centrifugal pumps.
Gear pumps.
Screw pumps.
Reciprocating pumps.
A connection between bilge and ballast line must be made by installing a ______.
Non-Return Valve
Globel Valve
Gate Valve
Ball Valve
When heated, fuel oil will ______.
increase in specific gravity
have a higher specific heat
expand in volume
increase in viscosity
The construction of the main propulsion engine lube oil sump should ________________.
retain the lube oil as long as possible before it recirculates through the system
have no plating joints of 90°
be provided with only a perfectly horizontal bottom
provide drain/return lines that are no greater than 24 inches from the pump suction
What might be the cause of marine diesel engine having an excessive consumption of lubricating oil?
Excessive piston ring wear
High lube oil viscosity
Insufficient lube oil temperature
Dirty lube oil filters
The flash point of a residual fuel should be used to determine the _____.
highest temperature to which the oil may be heated in a storage tank
highest temperature to which the oil may be heated for atomization
minimum temperature to which the oil should be heated for transferring
minimum temperature to which the oil should be heated in the fuel oil heater
A hydraulic actuator is a device that uses hydraulic energy coming from a hydraulic pump and produces linear mechanical power. What particularly is the component of the device that produces linear mechanical power?
Hydraulic cylinder
Hydraulic pump
Hydraulic motor
Hydraulic clutch
Burning fuel with a high sulfur content in a diesel engine will ____________.
produce corrosion in the cylinder and exhaust system at low loads
increase thermal efficiency
cause clogging of the fuel system
increase the ability of the engine to start in cold weather
it forms a corrosive acid when mixed with water or water vapor
it causes excessive smoking and soot at low firing rates
it doesn’t readily burn when combined with oxygen
it clogs fuel oil strainers more often
What is the best gasket material to use in cargo fuel oil lines?
Oil-resistant sheet packing
Minimize the effect of a listing condition
Unvulcanized packing
Cork sheet packing
Fuel oil viscosity to the atomizer can be reduced by ________.
increasing the fuel oil heater steam supply
mixing heavier oil with the fuel
changing the atomizer orifice size
increasing fuel oil pressure
The BTU value of fuel oil is determined by a/an _______.
calorimeter
open cup test
viscosimeter
hydrometer
What would you do first to prevent oil from escaping into the sea when ballasting through a cargo piping system?
Start the cargo pump, then open sea suction valves
Open sea suction valve, then start the cargo pump
Open block valves, then start the cargo pump
Open sluice valves, then start the cargo pump
Which of the following signs may indicate there is serious water contamination in the M/E lube oil system ?
Whitish lube oil
Partly corroded piston rings
Yellowish lube oil
Poor performance of the engine
Which component of a hydraulic system would enable the pump to be temporarily shutdown. And yet provide an instantaneous source of hydraulic oil?
Accumulator
pressure compensator valve
modulator
sump actuator
What should be done before performing any maintenance on a hydraulic system storing energy in an accumulator?
Bleed off all pressure within the system
Pressurized the system to test for leaks
Operate the machine until it reaches normal temperature
Disconnect the pump pressure control switch
A vessel whose fuel tanks are half full is subject to ___________
free surface effect
severe sagging
serious loss of reserve buoyancy
severe hogging
Demulsibility of a lube oil is defined as _________________.
the ability of oil to separate from water
the temperature at which oil flows rapidly
a measure of the water in a lube oil system
an emulsion of different grades of oil
Oily water separators perform the following function?
They make sure that no oil is pumped overboard.
They clean engine scavenges.
They remove the water from the fuel before it is burnt.
They make sure that no raw sewage is pumped overboard.
Which of the following describes one of the functions of the ballasting system?
To stabilize the ship by flooding certain designed tanks with seawater
To permit flooding of any fuel oil storage tank on any class of ship
To use it as a secondary service system
To store reserve feed or potable water for extended cruises
What procedure must be done in order to have the fuel oil viscosity entering the atomizer be reduced?
Increase the supply of steam to fuel oil heater
Use lighter kind of fuel oil
Increase the fuel oil specific gravity
Increase the delivery pressure of fuel oil
Oil mist detector takes a succession of air samples from all the compartments within the crankcase. When is the oil mist detector alarm activates?
When the concentration of mist is of the least amount needed for ignition which is 2-5%
When the concentration of mist is of the least amount needed for ignition which is 1%
When the concentration of mist is of the least amount needed for ignition which is 6-10%
When the concentration of mist is of the least amount needed for ignition which is 15%
Which of the pumps listed is normally used in fuel oil service systems?
positive displacement rotary
two-stage centrifugal
nonvented plunger
explosion proof gear
The purpose of the relief valve in a fuel oil service system is to ________.
protect the service pump from high discharge pressure
regulate the atomizer oil pressure
control the oil pressure regulators.
supply constant pressure to the burner combustion control valves
The boiler fuel oil service pump normally takes suction from the _______.
fuel oil settler tank
fuel oil heater discharge
contaminated drain inspection tank
double bottom fuel tanks
The fuel oil meter in the fuel oil service system should be bypassed when ______.
warming the oil in the burner headers by recirculation prior to boiler light off
transferring fuel from storage to settler tank to avoid erroneous fuel consumption readings
conducting programmed routine maintenance of the meter while underway
finished with engines is given by the bridge
When warming up a fuel oil service system, you should open the steam supply to the fuel oil heaters _____.
After you start the fuel oil service pump
Before you start the fuel oil service pump
Before you open the recirculating valve
Only if the setters are incapable of heating the oil
The valve located between the fuel oil header and the burner valve is known as the ___.
Root valve
Return valve
Header valve
Register valve
Machinery driving fuel oil transfer and fuel oil service pumps must be fitted with a remote means of stopping the machinery from ______.
outside the space concerned
within the space concerned
within the fireroom
the throttle station
Which of the following systems must have an emergency stop, protected with a glass enclosure, and located outside of the machinery space?
fuel oil service pump
main fire pump
all of the above
main circulating/bilge injection valve
The fins on the tubes of a fin type fuel oil heater are provided to ____.
Increase heater efficiency
Clean the fuel oil
Prevent tube erosion
Decrease fuel flow
The primary purpose of the heater used in a pressurized fuel oil system is to ____.
Reduce fuel oil viscosity for proper atomization
Reduce fuel oil specific gravity for better combustion
Increase the fire point of the fuel oil
Improve the flash point of the fuel oil
What will occur if the fuel oil heater condensate returns are not opened or are partially plugged?
Fuel may not be heated sufficiently for proper combustion
Fuel will become overheated
Fuel consumption will decrease
Fuel pump slippage will result
Failure of the fuel oil service pump to maintain fuel oil flow to the burner could be caused by ____.
Dirty fuel oil strainers
A high relief valve setting
Excessive return line oil pressure
Excessive fuel pump speed
The minimum temperature requirements for fuel oil in storage tanks is related to the _______.
pumpability of the oil
firepoint of the oil
size of the vents
size of the containment area in case of overflow
The rate of expansion of heated fuel oil varies with the ______.
Specific gravity
conductivity
volume
An emergency bilge suction is required for _____.
machinery space bilges
ballast tanks
sludge tanks
cargo hold bilges
One characteristic of a lubricating oil adversely affecting the results of centrifuging is ____________.
low oil demulsibility
high TBN value
low oil floc point
low oil neutralization number
Oil emulsification in engine lubricating oils will tend to ____.
displace lubricating oil required in areas of friction
decrease sludge formation in lubricating oil
cause water to separate from the oil
improve the lubricating oil viscosity
The function of lubricating oil is to ______________.
maintain a pressurized fluid film between moving surfaces
maintain even distribution of bearing wear
maintain a constant oil temperature
remove entrained water
An oil fog lubrication system is recommended for __________.
high speed continuous operation of roller bearings
gear shaft bearings
heavily loaded and high speed ball bearings
low and moderate speed ball bearings
To ensure adequate lubrication and to prevent a high operating temperature, the recommended amount of grease in a ball or roller bearing is approximately _________________.
35-40% of the void space in the bearing
10-15% of the void space in the bearing
90-95% of the void space in the bearing
65-70% of the void space in the bearing
The lignum vitae in a stern tube bearing is normally lubricated with ______.
water
grease
oil
tallow
Adsorption filters are not commonly used in steam turbine or diesel engine lubricating systems because they ____________.
remove additives from the lube oil
utilize exotic and expensive filtering media making them too costly for use.
are only effective at temperatures below 100°F
can adsorb no more than five times their weight in water
The substance primarily responsible for heat loss in the combustion process is _____________.
nitrogen
sulphur
carbon
hydrogen
One function provided by a hydraulic accumulator is to _____.
Absorb sudden changes in hydraulic fluid flow occurring in the system
Provide an area where air can separate from the oil
Provide an area to separate solid contaminants from the oil
Act as an oil and water separator
The component used in a hydraulic system to store potential energy in the form of hydraulic fluid under pressure, is the _____.
Ram
Pump
Piping
How can the chance of contaminating hydraulic fluid be decreased when working on hydraulic systems?
Clean the fittings before they are disconnected.
Place drip pans under leaky fittings.
Seal any cracks in lines with Permatex.
Coat all threads with graphite oil.
The volatility of any oil may be indicated by _____________. I. the flash point II. the fire point III. the autogenous ignition point
I, II and III
I only
I and II only
II and III only
The term 'pour point' is defined as the lowest temperature at which lubricating oils will flow ____________.
by gravity
rapidly
at a rate of 60cc per second
through a standard orifice at a specified temperature
Which of the following problems occurring in a hydraulic system can be caused by the use of an oil having a viscosity lower than specified?
The degree to which the viscosity of an oil will change with a change in temperature is indicated by the _______________.
viscosity index
weight designation
thermal change value
Which of the following precautions should be observed concerning the introduction of a fire resistant fluid into a hydraulic system?
Deterioration of paints, seals, metals, and electrical insulation may occur.
Fluid viscosity always increases as a normal result of its use.
Decreased wear rates of components is an advantage of its use.
Only chemically active filters may be used.
Which characteristic or condition will have the greatest effect on increasing a hydraulic oil’s viscosity?
pressure
cloud point
vacuum
Increased internal leakage, in addition to poor hydraulic system response, and inadequate lubrication, is the result of _____.
low hydraulic oil viscosity
pump bearings in poor condition
excessively worn actuator-piston packing
broken directional control valve centering springs
The major source of chemical contaminants in hydraulic fluid is _____.
oxidation by-products
microscopic steel shavings
abrasive waste
anti-oxidant compounds
Purging air from a hydraulic system is necessary when _____.
the system has been drained and then filled with new oil
adding small amounts of oil to the system
the system has been overheated
the system has been idle for a long period of time
Sluggish response or action of the hydraulic actuators may be a result of _____.
excessively high oil viscosity
insufficient load
reservoir level being maintained two inches above normal
relief-valve pressure setting too high
Cavitation in a hydraulic pump is indicated by noisy pump operation and can be caused by a/an _____.
clogged suction strainer in the reservoir
high fluid level in the reservoir
hydraulic fluid low floc point
excessive discharge pressure from the pump
Air trapped in one end of a hydraulic actuator may be indicated by _____.
erratic or jerky motion of the actuator
a pump discharge pressure that is consistent, but higher than normal
consistently faster response or movement of the actuator
overspeeding of the pump
Energy losses occurring in a hydraulic system are ultimately absorbed by the _____.
atmosphere as heat
reservoir expansion chamber
hydraulic piping flexibility
fluid as friction
Overheating of the hydraulic fluid in an electro-hydraulic anchor windlass can result from a/an _____.
low fluid viscosity around the shaft seal
overload on the pump motor
low fluid level in the reservoir
high oil level in the sump
The rate of fouling on the oil side of fuel heaters is directly related to the _______.
steam pressure in the heater
shape of the heating coils in the heater
oil pressure in the heater
rate of oil flow through the heater
