NEW
Font size
WorksheetsMotor 07
Total questions: 50
Worksheet time: 25mins
Generating tubes in waste heat boilers are finned to __________.
reduce gas flow turbulence
prevent exhaust gas corrosion
increase the rate of combustion
increase the rate of heat transfer
Which of the following is necessary for all waste heat boiler installations, regardless of design or manufacturer?
A means to control of evaporation
An independent means to prevent feedwater contamination
Installation of a powered circulating booster pump
Installation of a superheater
When accumulated carbon at the air inlet ports of a two-stroke/cycle diesel engine is being removed, you should take care to avoid carbon __________.
entering the cylinder
particles becoming lodged under the intake valves
entering the water jacket
particles entering lube oil
A three-way thermostatic control valve regulates the diesel engine cooling water temperature by passing a portion of the water __________.
around the engine
around the cooler
to the expansion tank
overboard
Failure of the feed pump to deliver feedwater to an auxiliary boiler could be caused by __________.
a low pump suction lift
abnormally low water temperature
grounded probes in the water level control
a high pump suction head
Which letter represents the exhaust gas exit point for the diesel engine shown in the illustration?
"K"
"J"
"N"
"V"
In which of the following areas of a crosshead engine is a permanently connected fire extinguishing system required?
Exhaust manifolds in excess of eight inches in diameter.
Crankcases having a gross volume in excess of 21 cubic feet.
Turbocharger inlet piping in excess of twelve inches in diameter.
Scavenging spaces in open connection to the cylinders.
The diesel engine component labeled "Z", shown in the illustration is called the __________.
inlet valve bridge
EGT monitor
exhaust valve bridge
scavenging air inlet
The diesel engine component labeled "1", shown in the illustration is called a/an __________.
inlet valve spring
external thread
conical speed/surge prevention device
exhaust valve spring
The port-and-helix metering pumps, used in diesel fuel injection systems, are usually designed to produce a constant beginning and a variable ending of fuel injection. These pumps are usually __________.
timed for port opening
timed for port closing
controlled by cam stroke
controlled by plunger stroke
The upper edges of the piston rings, shown in the illustration are rounded off to __________.
obtain increased strength
reduce oil pumping
keep the ring from sticking in the grove
reduce the probability of ring fracture
One operating characteristic of the reversing reduction gear unit, shown in the illustration, is that once a clutch is engaged, the __________.
engine torque is normally transmitted to the propeller shaft without slip
slip is produced by backlash in the thrust bearings
second clutch may be engaged for additional torque
idle clutch is fully expanded to hold its gear train stationary
During the operation of the fuel oil centrifuge shown in the illustration, it is found that the 'clean' oil discharge contains water. The most probable cause is the __________.
gravity disk is too large
throughput is too high
separating temperature is currently 95°C (203°F)
clean oil outlet valve has not been fully opened
Valves used in diesel engine fuel oil pressure piping are to be __________.
so constructed as to permit packing under pressure
solenoid released upon the failure of engine lubrication
either of the gate or globe valve type
forge constructed under the approval of the Marine Inspector
In the past, the interior sides of most centrifugal purifier bowls were straight. However, the interior side of the bowl shown in the illustration, as compared to a straight interior vertical side bowl, is designed to __________.
allow a greater volume of sealing water to be carried
assist in the self-cleaning process
assist in reducing the thickness of the emulsion interface
eliminate the need for a discharge ring
What type of fitting is to be used on diesel engine fuel injection line piping?
Mild steel
Hardened steel
Extra heavy
Double extra heavy
The butterfly valve overspeed device, shown in the illustration, is actuated by the engine overspeeding, resulting in __________.
an increase in oil pressure acting against the piston rod
a counterclockwise rotation of the butterfly valve to shut off the air to the engine
an increase in compression on the spring
the piston rod moving to the right due to spring force
Which of the following factors tends to increase scale formation on the saltwater side of a heat exchanger used in a diesel engine cooling water system?
Baffle plates that have been bent during prior removal.
Leaks in the cooler tube nest.
Operating the engine while maintaining a high sea water outlet temperature.
A punctured sea water strainer supplying cooling water to the heat exchanger.
In a full flow type lube oil system, the bypass relief valve will lift due to __________.
a clogged filter element
excessive lube oil pump discharge pressure
excessive lube oil flow
excessively hot lube oil
The device shown in the illustration is used to secure the air supply to a diesel engine when the engine overspeeds. In order for this to occur, supplied oil pressure must __________.
move the piston rod to the left
move the piston rod to the right
decrease allowing the spring to move the piston rod to the right
decrease allowing the butterfly valve to turn counterclockwise
Kingsbury thrust bearings are lubricated by __________.
flooding the thrust bearing assembly with oil
submerging oil wiper rings in an oil bath
pressure lubricating through internal passages
spraying oil directly on the thrust collar and shoes
In diesel engines, the four basic events (intake, compression, power and exhaust) are performed once in __________.
two crankshaft revolutions in a two-stroke/cycle engine
two power strokes in a two-stroke/cycle engine
one power stroke in a two-stroke/cycle engine
two piston strokes in a two-stroke/cycle engine
When installing the bearing cap on the device shown in the illustration, which of the precautions listed must be observed?
If the device is covered with abrasive material or contaminates, the unit may be reassembled, provided an abnormal method of reassembly is followed.
After applying anti-seize to the external threads, tighten one side at a time to the final torque value using a quality torque wrench.
Once the bearing cap bolts are properly torqued, insure that the end gap dimensions do not exceed a difference of 0.2 mm to ascertain even tightening of the cap.
Prior to installing the cap, position the thrust shoes in their proper locations.
Modern marine diesel engines using mechanical fuel injection, operate on a combustion cycle which is __________.
a combination of constant volume and constant pressure
a combination of constant temperature and constant pressure
entirely constant pressure
entirely constant volume
An emergency diesel generator should automatically shut down in the event of __________.
dangerous overspeeding
a loss of lube oil pressure
the activation of the fixed CO2 system for the emergency generator space
all of the above
The device labeled "A", shown in the illustration, is known as the __________.
centripetal pump cover
bowl assembly hood
regulating ring
kinetic converter
If the valve tappets in a diesel engine are set at greater clearances than those specified by the engine manufacturer, those valves will __________.
open late and close early
open late and close late
fail to open when the engine is cold
fail to open at normal operating temperature
During the normal operation of the centrifuge shown in the illustration, the operating liquid solenoid and bypass valves for the cleaning cycle should be in which position?
The solenoid valve is closed and the bypass valve is open.
The solenoid valve is closed and the bypass valve is closed.
The solenoid valve is open and the bypass valve is closed.
The solenoid valve is open and the bypass valve is open.
In a diesel engine, when refitting piston rings you should __________.
I. check the ring gap at the smallest diameter of the cylinder
II. remove carbon from the ring groove
I only
II only
both I and II
neither I nor II
As illustrated, what is the maximum allowable clearance permitted between the bearing and the shaft along its vertical axis?
1.00 mm
0.30 mm
0.46 mm
0.80 mm
The RPM of "D" is 500 and hobbed with 42 teeth. If gears "A", "B", and "C" have 42, 60, and 32 teeth respectively, the RPM of "A" in the gear train illustration is __________.
147.37 RPM
142.22 RPM
266.67 RPM
394.74 RPM
The term 'diesel engine cylinder scavenging' means __________.
delivering more air into the cylinder than it would normally receive during an ordinary charging process
forcing the products of combustion out of the cylinder with the fresh air charge
collecting the air charge at the air cleaner
combustion and expansion of hot gas
The RPM of "D" is 500 and hobbed with 36 teeth. If gears "A", "B", and "C" have 72, 64, and 24 teeth respectively, the RPM of "A" in the gear train illustration is __________.
93.75 RPM
70.31 RPM
444.44 RPM
62.50 RPM
Which of the following conditions could be a cause of excessive fuel dilution of diesel engine lube oil?
Leaking fuel injectors
Lower than normal compression
Delayed fuel injection
All of the above are correct.
Comparing the exhaust gas output of each cylinder of a diesel engine is one method of determining if the engine load is balanced. This can be determined by the use of a __________.
tachometer
calorimeter
pedometer
pyrometer
Lube oil in the fresh water cooling system of a diesel engine may result from a __________.
camshaft seizure
lube oil pump failure
lube oil cooler failure
lube oil sump overflow
Under what condition would valves "4" and "5", as shown in the illustration, be closed?
Operating the main engine on D.O.
Loading the HFO bunkers.
Operating in normal mode.
Operating D.O. purifier on HFO.
In the illustration shown, under what conditions would valves "2" and "3" be closed and valve "6" be opened?
When the HFO centrifuges are being run as separators and clarifiers respectively.
When the HFO purifier is being run as DO purifier.
When the DO purifier is being is being run as the HFO purifier.
When the HFO purifiers are being run in parallel.
The side pressure per unit of area, resulting from the angularity of the motion of the connecting rod, depends primarily on the __________.
weight of the piston
length of the piston
length of the cylinder liner
speed of the engine
The TBN value of diesel engine lube oil refers to its ability to __________.
resist changes in viscosity with changes in temperature
resist emulsification
neutralize acids
resist oxidation at high temperatures
When attempting to restart a warm high-speed engine, which of the following reactions can you expect?
Excessive fuel use
Higher than normal temperatures for start up
Longer starting periods
Higher than normal lube oil pressure
Which of the following conditions would require the removal of a turbocharger for repair?
Excessive oil consumption
Broken blades
High vibration
All of the above
Electric starting motors for diesel engines require high current for their operation. As a result of this, they __________.
have a generator as a source of power
need a current-voltage regulator for proper operation
are designed as shunt type DC motors
will carry a 100% overload for a brief period
The main advantage of unit injectors over other fuel injection systems is __________.
the lack of high pressure fuel lines
their relatively low injection pressures
reduced wear of spray orifices
the reduced probability of fuel leaks contaminating the engine lube oil sump
The device shown in the illustration, is known as a __________.
sliding piston type self cleaning centrifuge
sliding bowl type self cleaning centrifuge
solid bowl type self cleaning centrifuge
variable displacement axial piston pump
The pilot valves in an air pilot starting system for a two-stroke/cycle, direct-reversing, main propulsion diesel engine are operated by either a ported distributor disc or a/an __________.
regulator valve
quick opening main air valve
pilot air start check valve
individual cam for each pilot valve
Valve rotators are commonly used on which of the listed diesel engine cylinder head valves?
Air starting
Cylinder relief
Exhaust
Blow down
The impeller in area "A", shown in the illustration, is powered by __________.a
air
exhaust gas
water
oil
'Loop,' 'uniflow,' 'crossflow,' and 'return-flow' are terms used to describe various types of __________.
control air circuits
supercharging
turbochargers
scavenging
When may the crankcase ventilation pipes or oil drain pipes of two or more engines be connected?
Propulsion engines under 1000 shaft horsepower may share a common crankcase vent provided the oil drains remain separate.
In most cases it is desirable and cost effective for propulsion engines to share a common crankcase ventilation and monitoring system.
No interconnection may be made between the crankcase ventilation pipes or oil drain pipes.
None of the above are correct.
