6032244
Pregunta 1
Pregunta
Which of the following problems occurring in a hydraulic system could cause the use of an oil having a viscosity lower than specified?
Respuesta
-
Increased power consumption
-
Seal deterioration
-
Fast response and hunting
-
Oil film breakdown
Pregunta 2
Pregunta
The portion of a hydraulic hose that determines its overall strength, is the_________.
Respuesta
-
braided inner layer(s)
-
inner tube
-
outer cover
-
outer armor
Pregunta 3
Pregunta
The pour point of lubricating oils is affected the most by which of the following?
Respuesta
-
Extensive centrifuging
-
Wax content
-
Water content
-
Acid content
Pregunta 4
Pregunta
The neutralization number of lube oil used in the machinery has exceeded its permissible range, therefore, it will be necessary to ______.
Respuesta
-
renew the entire oil supply
-
add make-up oil
-
purify the oil
-
operate the machinery at reduced power
Pregunta 5
Pregunta
An organic solid lubricant, such as graphite, is suitable as an oil additive when used in_______________.
Respuesta
-
machinery bearings subjected to high temperatures
-
antifriction bearings on general service pumps
-
bearings subject to fluctuating loads
-
line shaft bearings
Pregunta 6
Pregunta
A filter used in a multi-operation hydraulic system would most likely be located______.
Respuesta
-
between the pump and the directional control valves
-
at the pump suction
-
between the control valves and the actuators
-
in the actuator return lines
Pregunta 7
Pregunta
What is the harmful effect of sulfur in a fuel?
Respuesta
-
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
Pregunta 8
Pregunta
Additives commonly found in turbine lubricating oil includes,______________.
Respuesta
-
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
Pregunta 9
Pregunta
The ash content of a fuel oil is significant to the operating engineer because it_____.
Respuesta
-
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
Pregunta 10
Pregunta
Dirt should not be allowed to contaminate a grease lubricant because the_______.
Respuesta
-
dirt is very abrasive when mixed with grease
-
bearings will leak oil excessively
-
dirt will cause corrosion of bearing
-
grease will become inflammable
Pregunta 11
Pregunta
Most fuel injection nozzles are opened by ______________.
Respuesta
-
fuel oil pressure
-
a cam operated follower
-
a spring-loaded pressure plate
-
timing gears keyed to the crankshaft
Pregunta 12
Pregunta
Proper atomization of fuel in diesel engine combustion chambers will _____________.
Respuesta
-
improve combustion
-
affect the injection pressure
-
reduce compression pressure
-
decrease power output
Pregunta 13
Pregunta
Differential needle valves used in fuel injectors are directly closed by _____________.
Respuesta
-
spring force
-
cam action
-
fuel oil pressure
-
firing pressure
Pregunta 14
Pregunta
Which these can seriously damage fuel injection equipment caused by poor combustion and leads to excessive cylinder liner wear?
Respuesta
-
Water
-
Carbon
-
Viscosity
-
Density
Pregunta 15
Pregunta
Fuel injectors used in heavy fuel oil systems are usually provided with cooling to reduce _________.
Respuesta
-
carbon accumulation on the nozzles
-
cold corrosion of the nozzles
-
fuel viscosity for better atomization
-
fuel detonation in the cylinders
Pregunta 16
Pregunta
How should the fire main outlet valves, or hydrants be installed?
Respuesta
-
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
Pregunta 17
Pregunta
An incorrect spray pattern produced by a diesel engine fuel injection nozzle can be directly caused by ____________.
Respuesta
-
overcooling of the nozzle
-
incorrect fuel rack setting
-
low firing pressure
-
excessive lube oil temperature
Pregunta 18
Pregunta
Fuel is admitted to a diesel engine cylinder through the _______________.
Respuesta
-
injector nozzles
-
intake valves
-
carburetor
-
exhaust ports
Pregunta 19
Pregunta
Fuel consumption is usually measured by a flow meter with a unit of __________.
Respuesta
-
kg/h
-
m°/s
-
m/c
-
tons/hr
Pregunta 20
Pregunta
What kind of lubrication wherein the contact surfaces are completely separated by an oil film?
Respuesta
-
Hydrodynamic
-
Mixed lubrication
-
Boundary lubrication
-
Forced lubrication
Pregunta 21
Pregunta
Maintaining the proper fuel oil temperature will result in _____________.
Respuesta
-
improved atomization
-
the elimination of valve wear
-
a decrease in cylinder blow-by
-
an increase in cylinder blow-by
Pregunta 22
Pregunta
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?
Respuesta
-
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
Pregunta 23
Pregunta
What is the main advantage of unit injectors over other fuel injection system?
Respuesta
-
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
Pregunta 24
Pregunta
What is the purpose of an accumulator in a hydraulic system?
Respuesta
-
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
Pregunta 25
Pregunta
Fuel oil discharged to the diesel engine cylinder is atomized at the _____________.
Respuesta
-
injector nozzle tip
-
turbocharger
-
carburetor
-
fuel oil pump
Pregunta 26
Pregunta
Which of the following fuel oil characteristic is being used in the calculation / computations of quantity?
Respuesta
-
Density
-
Viscosity
-
Flash point
-
Water content
Pregunta 27
Pregunta
On purifiers, as a rule of thumb, the time interval set between automatic de-sludging of 180 cst heavy fuel oil should be .............. ?
Respuesta
-
2 to 3 hours
-
1 to 2 hours
-
4 to 6 hours
-
6 to 8 hours
Pregunta 28
Pregunta
A segregated ballast system is a system where ___________.
Respuesta
-
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
Pregunta 29
Pregunta
In the diesel cycle, at what stage of the compression stroke is fuel injected inside the cylinder?
Respuesta
-
Before the end
-
At the beginning
-
At the end
-
After the end
Pregunta 30
Pregunta
How are hydraulic valve lash adjusters on diesel engine rocker arm assemblies lubricated?
Respuesta
-
By forced lube oil supply
-
By sealed self-lubricators
-
By metered hydraulic oil supply
-
By cup-fed grease
Pregunta 31
Pregunta
On a gear pump, what is the usual method of reducing the delivery pressure?
Respuesta
-
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.
Pregunta 32
Pregunta
When taking over the engine room watch, what should you check concerning the operational lubricating oil purifier ?
Respuesta
-
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.
Pregunta 33
Pregunta
Fuel injectors used in heavy fuel oil systems are usually provided with cooling to reduce _________.
Respuesta
-
carbon accumulation on the nozzles
-
cold corrosion of the nozzles
-
fuel viscosity for better atomization
-
fuel detonation in the cylinders
Pregunta 34
Pregunta
Fuel injection systems meter fuel, atomize fuel and ____________.
Respuesta
-
inject fuel at the proper time
-
create turbulence in the combustion chamber
-
aid in completing cylinder scavenging
-
minimize fuel penetration into the cylinder
Pregunta 35
Pregunta
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 ?
Respuesta
-
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..
Pregunta 36
Pregunta
For a continous operation of diesel engine, why is it that the use of a duplex filter unit would be the best arrangement?
Respuesta
-
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
Pregunta 37
Pregunta
Which characteristic of fuel oil is the most significant when determining the temperature to which the fuel oil must be heated for proper atomization?
Respuesta
-
viscosity
-
flashpoint
-
pour point
-
specific gravity
Pregunta 38
Pregunta
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 _____.
Respuesta
-
the circuit breaker
-
for leaks in the suction piping
-
relief valve is not properly seated
-
the suction strainer
Pregunta 39
Pregunta
Which type of pump would be most suitable for pumping large quantities such as oil cargoes ?
Respuesta
-
Centrifugal pumps.
-
Gear pumps.
-
Screw pumps.
-
Reciprocating pumps.
Pregunta 40
Pregunta
A connection between bilge and ballast line must be made by installing a ______.
Respuesta
-
Non-Return Valve
-
Globel Valve
-
Gate Valve
-
Ball Valve
Pregunta 41
Pregunta
When heated, fuel oil will ______.
Respuesta
-
increase in specific gravity
-
have a higher specific heat
-
expand in volume
-
increase in viscosity
Pregunta 42
Pregunta
The construction of the main propulsion engine lube oil sump should ________________.
Respuesta
-
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
Pregunta 43
Pregunta
What might be the cause of marine diesel engine having an excessive consumption of lubricating oil?
Respuesta
-
Excessive piston ring wear
-
High lube oil viscosity
-
Insufficient lube oil temperature
-
Dirty lube oil filters
Pregunta 44
Pregunta
The flash point of a residual fuel should be used to determine the _____.
Respuesta
-
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
Pregunta 45
Pregunta
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?
Respuesta
-
Hydraulic cylinder
-
Hydraulic pump
-
Hydraulic motor
-
Hydraulic clutch
Pregunta 46
Pregunta
Burning fuel with a high sulfur content in a diesel engine will ____________.
Respuesta
-
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
Pregunta 47
Pregunta
Fuel is admitted to a diesel engine cylinder through the _______________.
Respuesta
-
injector nozzles
-
intake valves
-
carburetor
-
exhaust ports
Pregunta 48
Pregunta
What is the harmful effect of sulfur in a fuel?
Respuesta
-
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
Pregunta 49
Pregunta
What is the best gasket material to use in cargo fuel oil lines?
Respuesta
-
Oil-resistant sheet packing
-
Minimize the effect of a listing condition
-
Unvulcanized packing
-
Cork sheet packing
Pregunta 50
Pregunta
Fuel oil viscosity to the atomizer can be reduced by ________.
Respuesta
-
increasing the fuel oil heater steam supply
-
mixing heavier oil with the fuel
-
changing the atomizer orifice size
-
increasing fuel oil pressure
Pregunta 51
Pregunta
The BTU value of fuel oil is determined by a/an _______.
Respuesta
-
calorimeter
-
open cup test
-
viscosimeter
-
hydrometer
Pregunta 52
Pregunta
What would you do first to prevent oil from escaping into the sea when ballasting through a cargo piping system?
Respuesta
-
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
Pregunta 53
Pregunta
Which of the following signs may indicate there is serious water contamination in the M/E lube oil system ?
Respuesta
-
Whitish lube oil
-
Partly corroded piston rings
-
Yellowish lube oil
-
Poor performance of the engine
Pregunta 54
Pregunta
Which component of a hydraulic system would enable the pump to be temporarily shutdown. And yet provide an instantaneous source of hydraulic oil?
Respuesta
-
Accumulator
-
pressure compensator valve
-
modulator
-
sump actuator
Pregunta 55
Pregunta
What should be done before performing any maintenance on a hydraulic system storing energy in an accumulator?
Respuesta
-
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
Pregunta 56
Pregunta
A vessel whose fuel tanks are half full is subject to ___________
Respuesta
-
free surface effect
-
severe sagging
-
serious loss of reserve buoyancy
-
severe hogging
Pregunta 57
Pregunta
Demulsibility of a lube oil is defined as _________________.
Respuesta
-
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
Pregunta 58
Pregunta
Oily water separators perform the following function?
Respuesta
-
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.
Pregunta 59
Pregunta
Which of the following describes one of the functions of the ballasting system?
Respuesta
-
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
Pregunta 60
Pregunta
Fuel oil discharged to the diesel engine cylinder is atomized at the _____________.
Respuesta
-
injector nozzles
-
turbocharger
-
carburetor
-
exhaust ports
Pregunta 61
Pregunta
What procedure must be done in order to have the fuel oil viscosity entering the atomizer be reduced?
Respuesta
-
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
Pregunta 62
Pregunta
Oil mist detector takes a succession of air samples from all the compartments within the crankcase. When is the oil mist detector alarm activates?
Respuesta
-
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%
Pregunta 63
Pregunta
Which of the pumps listed is normally used in fuel oil service systems?
Respuesta
-
positive displacement rotary
-
two-stage centrifugal
-
nonvented plunger
-
explosion proof gear
Pregunta 64
Pregunta
The purpose of the relief valve in a fuel oil service system is to ________.
Respuesta
-
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
Pregunta 65
Pregunta
The boiler fuel oil service pump normally takes suction from the _______.
Respuesta
-
fuel oil settler tank
-
fuel oil heater discharge
-
contaminated drain inspection tank
-
double bottom fuel tanks
Pregunta 66
Pregunta
The fuel oil meter in the fuel oil service system should be bypassed when ______.
Respuesta
-
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
Pregunta 67
Pregunta
When warming up a fuel oil service system, you should open the steam supply to the fuel oil heaters _____.
Respuesta
-
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
Pregunta 68
Pregunta
The valve located between the fuel oil header and the burner valve is known as the ___.
Respuesta
-
Root valve
-
Return valve
-
Header valve
-
Register valve
Pregunta 69
Pregunta
Machinery driving fuel oil transfer and fuel oil service pumps must be fitted with a remote means of stopping the machinery from ______.
Respuesta
-
outside the space concerned
-
within the space concerned
-
within the fireroom
-
the throttle station
Pregunta 70
Pregunta
Which of the following systems must have an emergency stop, protected with a glass enclosure, and located outside of the machinery space?
Respuesta
-
fuel oil service pump
-
main fire pump
-
all of the above
-
main circulating/bilge injection valve
Pregunta 71
Pregunta
The fins on the tubes of a fin type fuel oil heater are provided to ____.
Respuesta
-
Increase heater efficiency
-
Clean the fuel oil
-
Prevent tube erosion
-
Decrease fuel flow
Pregunta 72
Pregunta
The primary purpose of the heater used in a pressurized fuel oil system is to ____.
Respuesta
-
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
Pregunta 73
Pregunta
What will occur if the fuel oil heater condensate returns are not opened or are partially plugged?
Respuesta
-
Fuel may not be heated sufficiently for proper combustion
-
Fuel will become overheated
-
Fuel consumption will decrease
-
Fuel pump slippage will result
Pregunta 74
Pregunta
Failure of the fuel oil service pump to maintain fuel oil flow to the burner could be caused by ____.
Respuesta
-
Dirty fuel oil strainers
-
A high relief valve setting
-
Excessive return line oil pressure
-
Excessive fuel pump speed
Pregunta 75
Pregunta
The minimum temperature requirements for fuel oil in storage tanks is related to the _______.
Respuesta
-
pumpability of the oil
-
firepoint of the oil
-
size of the vents
-
size of the containment area in case of overflow
Pregunta 76
Pregunta
What is the harmful effect of sulfur in a fuel?
Respuesta
-
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
Pregunta 77
Pregunta
The BTU value of fuel oil is determined by a/an _______.
Respuesta
-
calorimeter
-
open cup test
-
viscosimeter
-
hydrometer
Pregunta 78
Pregunta
When heated, fuel oil will ______.
Respuesta
-
increase in specific gravity
-
have a higher specific heat
-
expand in volume
-
increase in viscosity
Pregunta 79
Pregunta
The flash point of a residual fuel should be used to determine the _____.
Respuesta
-
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
Pregunta 80
Pregunta
Which characteristic of fuel oil is the most significant when determining the temperature to which the fuel oil must be heated for proper atomization?
Respuesta
-
viscosity
-
flashpoint
-
pour point
-
specific gravity
Pregunta 81
Pregunta
Fuel oil viscosity to the atomizer can be reduced by ________.
Respuesta
-
increasing the fuel oil heater steam supply
-
mixing heavier oil with the fuel
-
changing the atomizer orifice size
-
increasing fuel oil pressure
Pregunta 82
Pregunta
The rate of expansion of heated fuel oil varies with the ______.
Respuesta
-
Specific gravity
-
conductivity
-
viscosity
-
volume
Pregunta 83
Pregunta
An emergency bilge suction is required for _____.
Respuesta
-
machinery space bilges
-
ballast tanks
-
sludge tanks
-
cargo hold bilges
Pregunta 84
Pregunta
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 _____.
Respuesta
-
the circuit breaker
-
for leaks in the suction piping
-
relief valve is not properly seated
-
the suction strainer
Pregunta 85
Pregunta
The construction of the main propulsion engine lube oil sump should ________________.
Respuesta
-
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
Pregunta 86
Pregunta
Demulsibility of a lube oil is defined as _________________.
Respuesta
-
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
Pregunta 87
Pregunta
One characteristic of a lubricating oil adversely affecting the results of centrifuging is ____________.
Respuesta
-
low oil demulsibility
-
high TBN value
-
low oil floc point
-
low oil neutralization number
Pregunta 88
Pregunta
Oil emulsification in engine lubricating oils will tend to ____.
Respuesta
-
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
Pregunta 89
Pregunta
The function of lubricating oil is to ______________.
Respuesta
-
maintain a pressurized fluid film between moving surfaces
-
maintain even distribution of bearing wear
-
maintain a constant oil temperature
-
remove entrained water
Pregunta 90
Pregunta
An oil fog lubrication system is recommended for __________.
Respuesta
-
high speed continuous operation of roller bearings
-
gear shaft bearings
-
heavily loaded and high speed ball bearings
-
low and moderate speed ball bearings
Pregunta 91
Pregunta
To ensure adequate lubrication and to prevent a high operating temperature, the recommended amount of grease in a ball or roller bearing is approximately _________________.
Respuesta
-
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
Pregunta 92
Pregunta
The lignum vitae in a stern tube bearing is normally lubricated with ______.
Respuesta
-
water
-
grease
-
oil
-
tallow
Pregunta 93
Pregunta
Adsorption filters are not commonly used in steam turbine or diesel engine lubricating systems because they ____________.
Respuesta
-
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
Pregunta 94
Pregunta
The substance primarily responsible for heat loss in the combustion process is _____________.
Respuesta
-
nitrogen
-
sulphur
-
carbon
-
hydrogen
Pregunta 95
Pregunta
One function provided by a hydraulic accumulator is to _____.
Respuesta
-
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
Pregunta 96
Pregunta
The component used in a hydraulic system to store potential energy in the form of hydraulic fluid under pressure, is the _____.
Respuesta
-
Accumulator
-
Ram
-
Pump
-
Piping
Pregunta 97
Pregunta
How can the chance of contaminating hydraulic fluid be decreased when working on hydraulic systems?
Respuesta
-
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.
Pregunta 98
Pregunta
The volatility of any oil may be indicated by _____________.
I. the flash point
II. the fire point
III. the autogenous ignition point
Respuesta
-
I, II and III
-
I only
-
I and II only
-
II and III only
Pregunta 99
Pregunta
The term 'pour point' is defined as the lowest temperature at which lubricating oils will flow ____________.
Respuesta
-
by gravity
-
rapidly
-
at a rate of 60cc per second
-
through a standard orifice at a specified temperature
Pregunta 100
Pregunta
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?
Respuesta
-
Increased power consumption
-
Seal deterioration
-
Fast response and hunting
-
Oil film breakdown
Pregunta 101
Pregunta
The degree to which the viscosity of an oil will change with a change in temperature is indicated by the _______________.
Respuesta
-
viscosity index
-
weight designation
-
thermal change value
-
pour point
Pregunta 102
Pregunta
Which of the following precautions should be observed concerning the introduction of a fire resistant fluid into a hydraulic system?
Respuesta
-
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.
Pregunta 103
Pregunta
Which characteristic or condition will have the greatest effect on increasing a hydraulic oil’s viscosity?
Respuesta
-
pressure
-
pour point
-
cloud point
-
vacuum
Pregunta 104
Pregunta
Increased internal leakage, in addition to poor hydraulic system response, and inadequate lubrication, is the result of _____.
Respuesta
-
low hydraulic oil viscosity
-
pump bearings in poor condition
-
excessively worn actuator-piston packing
-
broken directional control valve centering springs
Pregunta 105
Pregunta
The major source of chemical contaminants in hydraulic fluid is _____.
Respuesta
-
oxidation by-products
-
microscopic steel shavings
-
abrasive waste
-
anti-oxidant compounds
Pregunta 106
Pregunta
Purging air from a hydraulic system is necessary when _____.
Respuesta
-
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
Pregunta 107
Pregunta
Sluggish response or action of the hydraulic actuators may be a result of _____.
Respuesta
-
excessively high oil viscosity
-
insufficient load
-
reservoir level being maintained two inches above normal
-
relief-valve pressure setting too high
Pregunta 108
Pregunta
Cavitation in a hydraulic pump is indicated by noisy pump operation and can be caused by a/an _____.
Respuesta
-
clogged suction strainer in the reservoir
-
high fluid level in the reservoir
-
hydraulic fluid low floc point
-
excessive discharge pressure from the pump
Pregunta 109
Pregunta
Air trapped in one end of a hydraulic actuator may be indicated by _____.
Respuesta
-
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
Pregunta 110
Pregunta
Energy losses occurring in a hydraulic system are ultimately absorbed by the _____.
Respuesta
-
atmosphere as heat
-
reservoir expansion chamber
-
hydraulic piping flexibility
-
fluid as friction
Pregunta 111
Pregunta
Overheating of the hydraulic fluid in an electro-hydraulic anchor windlass can result from a/an _____.
Respuesta
-
low fluid viscosity around the shaft seal
-
overload on the pump motor
-
low fluid level in the reservoir
-
high oil level in the sump
Pregunta 112
Pregunta
The rate of fouling on the oil side of fuel heaters is directly related to the _______.
Respuesta
-
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
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