Movers, Pump, Compressor & Lubrication Flashcards
1
Q
A prime mover is:
a) an electric motor
b) a steam turbine
c) a centrifugal pump
d) an air compressor
e) a boiler
A
a) an electric motor
2
Q
Large power production plants tend to be of the thermal type because they can burn solid fuels and:
a) they are the least expensive to build
b) the noise level is much less than internal combustion engines
c) the heat cycle they use is the most efficient
d) solid fuels are the most plentiful and cheapest
e) require the least amount of manpower
A
c) the heat cycle they use is the most efficient
3
Q
A steam engine will have the steam supply to the cylinder shut off once the piston has travelled
a) 25 to 35% of its stroke
b) 75 to 90% of its stroke
c) 15 to 20% of its stroke
d) 55 to 65% of its stroke
e) 90 to 95% of its stroke
A
a) 25 to 35% of its stroke
4
Q
The reciprocating motion of a steam engine is converted to rotary motion
a) at the end of the piston stroke
b) in the steam cylinder
c) via the valve eccentric
d) at the crankshaft
e) via the valve gear
A
d) at the crankshaft
5
Q
The crosshead of a steam engine
a) imparts angular motion to the piston rod
b) is where linear motion becomes angular motion
c) imparts linear motion to the piston rod
d) does not require any lubrication
e) never requires any special bearing material
A
b) is where linear motion becomes angular motion
6
Q
A steam engine piston
a) moves fastest at the end of its stroke
b) can never have steam applied to either side
c) is lubricated from the crankcase oil by splash method
d) moves fastest at the beginning of its stroke
e) never requires lubrication
A
d) moves fastest at the beginning of its stroke
7
Q
A routine inspection of an operating steam engine should cover first and foremost
a) lubricators
b) drive belts
c) engine speed
d) steam temperature
e) steam quality
A
a) lubricators
8
Q
Whenever feasibly possible, when checking bearings on running pieces of equipment it is wise to
a) check the oil quality leaving each
b) check the oil quantity leaving each
c) get accustomed to normal running temperature and
vibration by feel
d) smell the normal odours of the running bearing
e) observe the temperature on a thermometer
A
c) get accustomed to normal running temperature and
vibration by feel
9
Q
One of the first ways to detect a fault in a reciprocating engine is
a) by sound
b) temperature indication
c) performance efficiency
d) by oil consumption
e) by smell
A
a) by sound
10
Q
The slide valve of a steam engine is designed to
a) allow the piston to slide more freely
b) drain the condensate from the cylinder during warm-up
c) provide lubrication for the steam engine
d) provide for the steam to enter and leave the cylinder
e) prevent the engine from overspeeding
A
d) provide for the steam to enter and leave the cylinder
11
Q
A steam turbine’s exhaust can often supply a process with steam because
a) processes always require a lower steam pressure
b) processes never require the high steam temperatures turbines do
c) turbine exhaust steam is always dry and saturated
d) it is free of oil
e) the steam will be at a temperature above the initial
temperature
A
d) it is free of oil
12
Q
The exhaust steam from a steam turbine is more acceptable for process than the exhaust from a steam engine because
a) it is much hotter
b) it is easily controlled
c) it is free of oil
d) it is free of moisture
e) it contains more condensate
A
c) it is free of oil
13
Q
The exhaust steam from a condensing steam turbine
____________ than the exhaust from a steam engine:
a) is drier
b) has more vapour
c) is more contaminated
d) is hotter
e) has more moisture
A
e) has more moisture
14
Q
Turbines often have segmental carbon ring sealing glands which are held in place by
a) labyrinths
b) shrouding
c) drive screws
d) garter springs
e) thrust runners
A
d) garter springs
15
Q
A steam turbine should trip or shut down when normal
operating speed is exceeded by:
a) 250 RPM
b) 3 to 5%
c) 50 RPM
d) 10 to 15%
e) 25 RPM
A
d) 10 to 15%
16
Q
Condensing turbines:
a) are always impulse turbines
b) will have a vacuum in the last row of rotating blades
c) will use the condensate for heating
d) are very small units
e) cannot have counterflow stages
A
b) will have a vacuum in the last row of rotating blades
17
Q
Which turbine uses a condenser?
a) back pressure turbine
b) a turbine exhausting to a vacuum
c) a bleeder turbine exhausting at atmospheric pressure
d) a non-condensing extraction turbine
e) a turbine exhausting to atmosphere
A
b) a turbine exhausting to a vacuum
18
Q
The shrouding installed on the blading of a steam turbine serves to:
a) cool the blade tips
b) expand the steam
c) stop the steam flow
d) heat the steam
e) confine the steam to the blades
A
e) confine the steam to the blades
19
Q
The turbine overspeed trip:
- prevents the turbine from vibrating
- prevents the turbine exceeding the maximum rated speed
- is operated by a spring loaded pin in the rotating blades
- will close the steam stop valve
- should be tested before the turbine is placed in service
a) 2, 4, 5
b) 2, 3, 4, 5
c) 1, 2, 4
d) 3, 4, 5
e) 4, 5
A
a) 2, 4, 5
20
Q
The overspeed trip of a steam turbine:
a) operates on turbine vibrations due to high speed
b) is installed on all turbines
c) can be adjusted according to the load demand
d) is regulated by exhaust pressure
e) sheds the load in the event of high pressure
A
b) is installed on all turbines
21
Q
Turbine overspeed trip:
a) prevents the turbine from vibrating
b) will close the steam stop valve to the turbine
c) is operated by a spring loaded pin in the rotating blades
d) supplies the operator with rpm indications
e) reduces the turbine speed by increasing the back pressure
A
b) will close the steam stop valve to the turbine
22
Q
Turbine lubricating oil:
a) is not required for small impulse turbines
b) must be changed every four months
c) lubricates the blades
d) can be used to operate the turbine governor
e) should be preheated before use
A
d) can be used to operate the turbine governor
23
Q
The purpose of turbine glands is to prevent:
a) water from entering the turbine
b) steam from entering the turbine
c) steam escaping from the turbine
d) steam from entering the lubrication system
e) oil from entering the turbine
A
c) steam escaping from the turbine
24
Q
Shaft sealing in high output turbines is done with:
a) water seals
b) mechanical seals
c) wear rings
d) packing glands
e) labyrinth seals
A
e) labyrinth seals
25
When the steam pressure drop occurs in only the stationary members or components of a turbine, the turbine is known as:
a) a single stage unit
b) an impulse unit
c) a reaction unit
d) a Parsons unit
e) a cross compound reaction unit
b) an impulse unit
26
A large reaction turbine will have:
a) no thrust bearings
b) steam pressure dropping in only the moving sections
c) blades which are basically symmetrical in cross-section
d) never more than 5 stages
e) steam pressure dropping through moving and stationary sections
e) steam pressure dropping through moving and stationary sections
27
Turbine speed can be "fine tuned" with a device which will be limited to about 10% over the rated speed. This device is the:
a) governor valve
b) overspeed governor
c) sentinel valve
d) hand speed control
e) overspeed trip
d) hand speed control
28
Turbine thrust bearings are fixed to the casing and prevent axial movement of the spindle by contacting a component on the shaft known as a:
a) shaft sleeve
b) labyrinth
c) collar
d) shroud
e) diaphragm
c) collar
29
Shaft sealing carbon glands are:
a) lubricated by the main oil pump
b) limited to a temperature of 250 degrees C
c) replaced monthly due to erosion
d) self-lubricating
e) metal sprayed components
d) self-lubricating
30
The great majority of steam turbine governing systems utilize the:
a) hydraulic system principle
b) pneumatic system principle
c) mechanical centrifugal principle
d) lever principle
e) bimetal expansion principle
c) mechanical centrifugal principle
31
Reaction turbines:
a) have bucket shaped blades
b) have a pressure drop through the moving and stationary blades
c) are used for high pressures only
d) have a pressure drop in the moving blades only
e) have little axial thrust
b) have a pressure drop through the moving and stationary blades
32
In an impulse turbine:
a) the steam flow is reduced through the nozzles
b) the steam pressure is reduced in the nozzles
c) the steam pressure will drop across the blades
d) the steam velocity is increased through the blades
e) the exhaust steam is directed back to the boiler
b) the steam pressure is reduced in the nozzles
33
The steam turbine that has a pressure drop across
every set of blades is the __________ turbine.
a) double-stage impulse
b) single-stage impulse
c) topping
d) back pressure
e) reaction
e) reaction
34
When starting a steam turbine it is customary practice to:
a) analyze the oil for water prior to rolling
b) turn on all cooling water systems first
c) place the speed control system in service once the unit is rolling
d) test the overspeed trip as soon as running speed is
attained
e) stop the auxiliary oil pump as soon as steam begins to turn the unit
d) test the overspeed trip as soon as running speed is
| attained
35
Reaction turbines:
a) have all of the steam pressure drop take place
in the stationary nozzle
b) have a velocity increase in the fixed blading
c) are used for higher speed only
d) have a velocity decrease through the fixed blading
e) require little blade sealing
b) have a velocity increase in the fixed blading
36
The average amount of water volume which evaporates from a cooling tower is:
a) 2%
b) 10%
c) 15%
d) 5%
e) 3.5%
d) 5%
37
Natural draft cooling towers operate most effectively in large open spaces and:
a) where wind is relatively constant
b) where relative humidity is high
c) where a large body of water is nearby
d) require a windbreak
e) must not be in direct sunlight
a) where wind is relatively constant
38
Excessive wind velocity in a natural draft cooling tower may cause:
a) louvers to become broken
b) high water drift or losses
c) rotation reversal of the fan
d) over-cooling of the water
e) under-cooling of the water
b) high water drift or losses
39
Compared to a crossflow tower, a counterflow tower:
a) is not as tall
b) has much less capacity
c) requires less floor space
d) requires more fan power
e) has a higher pressure drop
c) requires less floor space
40
Water contained in the airstream at the discharge of a
cooling tower is removed:
a) with centrifugal separators
b) by a series of chevron dryers
c) by refrigeration means
d) by a series of baffles
e) with drift eliminators
e) with drift eliminators
41
A cooling tower which requires neither fan nor fill is the:
a) natural draft unit
b) counterflow induced unit
c) venturi unit
d) crossflow unit
e) forced draft unit
c) venturi unit
42
A valve which prevents water flow over the fill of a tower during cold weather should not be closed until the:
temperature reaches
a) - 0.5 degrees C
b) + 0.5 degrees C
c) + 5 degrees C
d) + 20 degrees C
e) + 27 degrees C
e) + 27 degrees
43
To prevent cooling tower basin water from freezing during cold weather many units are equipped with:
a) ethylene glycol antifreeze systems
b) electric basin heaters
c) propane burners
d) ice defrosters
e) warming tapes
b) electric basin heaters
44
You are replacing the cooling tower fan motor bearings because:
a) the motor was running single phase
b) windings in the motor were faulty
c) a noise which sounded like a bad bearing was heard
d) the rotor was rubbing the stator
e) the gear reducer pinion shaft was misaligned
d) the rotor was rubbing the stator
45
Scaling is not as severe in towers when compared to boilers because:
a) tower water does not evaporate
b) there are not as many dissolved solids in tower water
c) pressure is not as high
d) temperatures are not as high
e) water is constantly being aerated
d) temperatures are not as high
46
A gas turbine compressor is usually:
a) centrifugal type
b) downstream of the turbine
c) dynamic axial design
d) downstream of the combustor
e) driven by a motor
c) dynamic axial design
47
The compressor on the gas turbine:
a) can be driven by the load turbine
b) is always of the axial type
c) is always a multi-stage compressor
d) is always independently driven
e) is always a reciprocating type
a) can be driven by the load turbine
48
The combustion chamber of a gas turbine:
a) increases the pressure of the compressed air
b) is heated between the load turbine and the compression turbine
c) burns fuel with excess air
d) is water cooled
e) rotates at shaft speed
c) burns fuel with excess air
49
Many typical steam plant auxiliaries are eliminated with a gas turbine due to its:
a) small size
b) high speed
c) high power to weight ratio
d) simplicity
e) low oil consumption
d) simplicity
50
Gas turbines are very popular where:
a) noise does not present a problem
b) water is scarce
c) industrial sites are small and in congested areas
d) thermal pollution is of major concern
e) natural gas is plentiful
b) water is scarce
51
Gas turbines are ideal when considering:
a) long warm-up periods
b) emergency power generation
c) automotive power
d) cooling water pump operation
e) good thermal efficiency
b) emergency power generation
52
A two shaft gas turbine:
a) has the load turbine downstream from the compressor turbine
b) has the first turbine drive the prop on a turbo-prop engine
c) is always an open cycle type
d) is always a closed cycle type
e) does not require a starting motor
a) has the load turbine downstream from the compressor turbine
53
A gas turbine is not self-starting. It must be rotated at
__________ of its maximum speed before fuel is turned on.
a) 10% to 30%
b) 15% to 30%
c) 20% to 30%
d) 25% to 30%
e) 25% to 50%
c) 20% to 30%
54
Early gas turbines were handicapped by:
a) metal not being able to withstand high speed centrifugal forces
b) the inability to get enough air into the combustion
chamber
c) metals not standing the high temperatures involved
d) their high operating speeds
e) their inadequate power capability
c) metals not standing the high temperatures involved
55
The temperature to which the air can be raised at the turbine inlet is:
a) an indication of a unit's power
b) directly related to the unit's size
c) a function of the air compressor input
d) an indication of the unit's efficiency
e) important for proper compressor performance
d) an indication of the unit's efficiency
56
The output power of a gas turbine is directly related to the:
a) mass of gas passing through the turbine per second
b) temperature at the turbine inlet
c) mass of the unit
d) slippage between the turbine and compressor
e) turbine exhaust temperature
a) mass of gas passing through the turbine per second
57
The low installation cost of a gas turbine is:
a) due to cheap materials in the blades
b) due to short fuel lines
c) because no fuel pump is required
d) because no electrical wiring is required
e) because less auxiliary equipment is needed
e) because less auxiliary equipment is needed
58
Some of the characteristics which make the gas turbine a better choice over other prime movers are:
1. low maintenance
2. minimum cooling water
3. high thermal efficiency
4. rapid start-up and loading
a) 1, 2, 3, 4
b) 1, 2, 3
c) 1, 2, 4
d) 1, 3, 4
e) 2, 3, 4
c) 1, 2, 4
59
The air side of a gas turbine regenerator is located:
a) before the compressor
b) after the combustion chamber
c) between the turbine and combustion chamber
d) between the turbine and atmosphere
e) downstream of the compressor
e) downstream of the compressor
60
A gas turbine performs most effectively if:
a) lube oil is of the proper viscosity
b) cooling water temperature is kept low
c) ambient air temperature is high
d) ambient air temperature is low
e) loaded immediately after starting
d) ambient air temperature is low
61
A combined steam and gas turbine arrangement can be termed:
a) an ideal system
b) a cogeneration system
c) a once through system
d) ideal relative to system efficiency
e) a high capacity system
b) a cogeneration system
62
The purpose of a regenerator is:
a) to clean the exhaust gases
b) to improve the efficiency of the turbine
c) to increase the temperature in the combustion chamber
d) to lower the temperature in the combustion chamber
e) to recirculate the exhaust gases back through the compressor
b) to improve the efficiency of the turbine
63
In a compression ignition engine the fuel is ignited by:
a) an electric spark
b) the compressed air temperature
c) the atomized fuel
d) a cross-combustor
e) compressed air pressure
b) the compressed air temperature
64
Diesel engine governing is accomplished by:
a) varying the fuel quality
b) carburetion
c) varying the fuel quantity
d) fuel atomizing air quantity
e) fuel atomizing air pressure
c) varying the fuel quantity
65
The fuel for a diesel engine is:
a) light fuel oil
b) vaporised by a carburettor
c) mechanically atomized by high pressure
d) atomized before the cylinder
e) mixed with air before the cylinder
c) mechanically atomized by high pressure
66
Four-stroke cycle engine valves are:
a) operated by cams
b) of the pressure differential variety
c) a number of ports in the cylinder wall
d) often termed reed or channel valves
e) always open as the piston travels upwards
a) operated by cams
67
An engine which develops one power stroke with every other turn of the crankshaft is the:
a) two stroke diesel engine
b) type which requires pre-mixing lube oil and fuel
c) four stroke natural gas engine
d) V type engine
e) external combustion unit
c) four stroke natural gas engine
68
Four cycle engine lubrication is usually:
a) forced by pump
b) by gravity oilers
c) by the scoop method
d) by the dip tube method
e) by grease fitting
a) forced by pump
69
An example of an engine which gives high torque at low speeds would be that of a:
a) chain saw
b) two cycle snowmobile
c) four stroke motocross motorcycle
d) two cycle lawnmower
e) two cycle transit bus
c) four stroke motocross motorcycle
70
A two cycle engine:
a) must always have lube oil premixed with the fuel
b) can never have a crankcase lubrication system
c) can never be operated in an inverted position
d) "pops" twice as often as an equivalent cylinder four
stroke engine
e) gives one power stroke every other crankshaft revolution
d) "pops" twice as often as an equivalent cylinder four
| stroke engine
71
Pre-mixing lube oil and fuel or having a special lube oil
injection system is typical of the average:
a) snowmobile engine
b) automobile engine
c) aircraft engine
d) tractor engine
e) heavy equipment engine
a) snowmobile engine
72
A major difficulty encountered with a two-stroke cycle engine is:
a) the high torque at low speeds
b) maintenance of many moving parts
c) the difficulty in cold weather starting
d) the high speeds compared to an equivalent four stroke
engine
e) exhausting the spent gases from the cylinder
e) exhausting the spent gases from the cylinder
73
A two cycle gasoline engine:
a) has more moving parts than a four cycle
b) produces twice as much power as a four cycle
c) must have two cylinders
d) does not require exhaust valves
e) is of more simple construction than a four cycle
e) is of more simple construction than a four cycle
74
Cylinder scavenging:
a) is more efficient in a 2 cycle engine than a 4 cycle type
b) is scoring the cylinder by a broken piston ring
c) is the removal of exhaust gases from the cylinder
d) prevents the air from entering the cylinder
e) removes excessive oil from the cylinder walls
c) is the removal of exhaust gases from the cylinder
75
The purpose of a spark plug is:
a) to ignite the fuel air mixture in a gasoline engine
b) to produce power for the compression stroke
c) to prewarm the engine
d) to raise the ignition point of the fuel
e) to ignite the air in the cylinder
a) to ignite the fuel air mixture in a gasoline engine
76
Compression ignition engines:
a) need suction end discharge valves
b) will compress air only on the compression stroke
c) need a carburettor to mix the fuel with the air
d) will compress air only on the power stroke
e) require a spark timing device
b) will compress air only on the compression stroke
77
The injection pump of a diesel engine is driven by:
a) piston action
b) the governor
c) the wrist pin
d) the gudgeon pin
e) the camshaft
e) the camshaft
78
Ignition in a diesel engine is started by:
a) a glow plug
b) a spark plug
c) a starter motor
d) compression in the cylinder
e) air injection
d) compression in the cylinder
79
Using a compressed air starting motor is a popular method of starting a:
a) large stationary diesel engine
b) small two stroke engine
c) jet engine
d) high performance engine
e) natural gas engine
a) large stationary diesel engine
80
When using compressed air to each cylinder for starting purposes, the pressure is approximately:
a) 520 kPa
b) 255 kPa
c) 3,030 kPa
d) 2,100 kPa
e) 435 kPa
d) 2,100 kPa
81
Reduction in sealing qualities between the piston rings and cylinder wall by the lube oil may be the result of:
a) low cooling water temperature
b) high lube oil viscosity
c) high cooling water temperature
d) high carbon residue of the lube oil
e) wrong fuel being used
c) high cooling water temperature
82
```
A pump is capable of suction lift due to
a) its ability to convert kinetic energy into potential
energy
b) the speed at which it operates
c) its input power
d) its size
e) atmospheric pressure
```
e) atmospheric pressure
83
Centrifugal pumps do not develop good suction lift because:
a) atmospheric pressure is usually too low
b) the pumped medium relative density is too high
c) their internal component clearances are too high
d) the speed is too low
e) they favour pressure rather than volume
c) their internal component clearances are too high
84
It is generally accurate to say that:
a) 9.8 kPa pressure results from every metre of water depth or height
b) a water height or depth of 10.34 metres results in 1 kPa
c) 1 kPa will result from a water head of 9.8 metres
d) 10.21 kPa will result from 1 metre of static water head
e) atmospheric pressure has no bearing on static water head
a) 9.8 kPa pressure results from every metre of water depth or height
85
Preferably, dynamic pumps should be located:
a) directly under the liquid source when suction lift is
involved
b) above the liquid source when suction head is involved
c) above the liquid source when suction lift is involved
d) at the liquid source level when suction lift is involved
e) below the liquid source when suction head is involved
e) below the liquid source when suction head is involved
86
The vertical distance from the liquid surface up to the pump centre-line plus the vertical distance from the pump centre-line up to the surface of the liquid in the discharge tank is:
a) static discharge head
b) static suction head
c) suction lift
d) total discharge head
e) total static head
e) total static head
87
The difference between static suction head and static
discharge head is:
a) total static head
b) static discharge head
c) static suction head
d) equivalent head
e) dynamic head
a) total static head
88
When a pump discharges into a vessel operating at 300 kPa, the 300 kPa is referred to as:
a) dynamic head
b) equivalent head
c) discharge head
d) friction head
e) total head
b) equivalent head
89
The total static head of a pump:
a) is the capacity of the pump
b) is the difference between the static suction head and the static discharge head
c) is the discharge pressure in metres
d) is all the parts of the pump casing
e) is the discharge head of the pump
b) is the difference between the static suction head and the static discharge head
90
When a reciprocating pump discharges while its piston or plunger moves in only one direction, it is termed a:
a) positive displacement unit
b) single acting unit
c) dynamic unit
d) double acting unit
e) duplex unit
b) single acting unit
91
Centrifugal pumps convert rotating mechanical energy into kinetic energy then:
a) discharge the kinetic energy
b) back to mechanical energy
c) absorb the energy
d) into potential energy in the form of pressure
e) into centrifugal force
d) into potential energy in the form of pressure
92
A hot water heating system circulator should:
a) be directly coupled
b) have its own vibration-free base
c) be very quiet in operation
d) develop an extremely high differential pressure
e) not run continuously
c) be very quiet in operation
93
The capacity of a centrifugal pump:
a) varies with discharge pressure
b) can be altered by speed variation only
c) indicates that the unit is a positive displacement type
d) should be varied by suction valve manipulation
e) is fixed and can only be altered by changing the impeller
a) varies with discharge pressure
94
Centrifugal pump power requirements are decreased when:
a) discharge pressure is decreased
b) the litres moved per minute is decreased
c) the casing pressure drops
d) the discharge velocity is high
e) the discharge head is at minimum
b) the litres moved per minute is decreased
95
A rotary pump:
a) is a variety of dynamic unit
b) never has discharge pulsations
c) should be equipped with a relief valve
d) has the highest capacity of any pump
e) never requires cylinder lubrication
c) should be equipped with a relief valve
96
When starting-up a rotary pump you must be sure that the:
a) discharge valve is closed
b) discharge valve is open
c) pump is filled with air
d) pump is at the correct temperature
e) pump suction valve is closed
b) discharge valve is open
97
Rotary pumps:
1. are high pressure pumps
2. must be primed
3. use mechanical seals
4. are positive displacement pumps
a) 1, 2
b) 2, 3
c) 1, 4
d) 1, 3, 4
e) 1, 2, 3, 4
c) 1, 4
98
A double-acting pump:
a) has two pistons on the pump end
b) will always be driven by the steam pistons
c) has two pistons on the driver end
d) will have two slide valves
e) is a positive displacement pump
e) is a positive displacement pump
99
A volute type pump:
a) is a positive displacement pump
b) has a progressively expanding spiral casing
c) reduces the velocity in the discharge nozzle
d) is more costly than diffuser pumps
e) is a regenerative type pump
b) has a progressively expanding spiral casing
100
A diffuser pump:
1. has stationary guide vanes surrounding the impeller
2. has a higher efficiency than a volute type
3. has high suction lift
4. does not have to be primed
a) 1
b) 3
c) 2, 3
d) 1, 2
e) 4
d) 1, 2
101
Turbine pumps:
1. are high capacity pumps
2. are high pressure pumps
3. has the liquid gain energy in a number of impulses
a) 1
b) 1, 2
c) 2, 3
d) 1, 2, 3
e) 1, 3
c) 2, 3
102
A centrifugal pump consists of
a) an impeller surrounded by a casing
b) a piston moving to and fro in a cylinder
c) gears rotating in a housing
d) sliding vanes
e) pulsating disc
a) an impeller surrounded by a casing
103
The capacity of a centrifugal pump should only be reduced by:
a) throttling the suction valve
b) closing in the suction valve
c) closing in both the suction and discharge valves
d) opening the pump casing vent valve
e) closing in the discharge valve
e) closing in the discharge valve
104
Cavitation of a pump refers to, when:
a) the pump is filled with air
b) the pump is filled with vapour
c) the oil ring is damaged
d) the suction valve is open
e) the pump is steam driven
b) the pump is filled with vapour
105
Rotary pumps:
1. have tight clearances on all moving parts
2. deliver high pressure liquid without pulsations
3. are positive displacement units
4. should not be started with discharge closed
a) 1
b) 1, 2
c) 1, 2, 3
d) 1, 3, 4
e) 2, 3
d) 1, 3, 4
106
If a pump is cavitating what can you do to prevent
or reduce the cavitation?
a) close the casing vent valve
b) open the vent valve and close the suction valve
c) partially close the suction valve
d) close the discharge valve
e) raise the suction pressure
e) raise the suction pressure
107
A positive displacement stand by-pump will have:
a) the vent and drain valves open
b) the suction valve closed and the discharge valve open
c) the suction valve open and the discharge closed
d) the suction valve open and the discharge valve open
e) the suction valve and the discharge valves closed
d) the suction valve open and the discharge valve open
108
Pumps handling cryogenic materials operate:
a) as staged units
b) at extremely low temperatures
c) nearly always as dynamic units
d) as tandem units
e) as high speed units
b) at extremely low temperatures
109
A circulating pump is usually:
a) connected with some type of heat exchanger system
b) a once through device
c) mounted to the piping
d) a small capacity unit
e) a high head unit
a) connected with some type of heat exchanger system
110
A multi-stage pump would be used:
a) when the lift is great
b) when a greater volume must be pumped
c) when the head is great
d) when the temperature of the water being pumped is high
e) whenever there is sufficient boiler room floor space
c) when the head is great
111
Turbine pumps are best suited for:
a) low capacity low pressure service
b) low capacity high pressure service
c) high capacity high pressure service
d) high capacity low pressure service
e) heavy viscous fluids
b) low capacity high pressure service
112
Pump wear rings are installed on an impeller by set screws, threading or:
a) shrinking
b) welding
c) brazing
d) soldering
e) forging
a) shrinking
113
Wear rings are usually constructed of
a) ceramics or aluminum
b) graphite or bronze
c) bronze or cast iron
d) steel or alloy steel
e) wrought iron or pig iron
c) bronze or cast iron
114
Wearing rings:
1. are used on impellers
2. are used on the casing
3. give protection to the shaft
4. reduce the maintenance cost of the pump
a) 1, 2, 3
b) 1, 2, 4
c) 2, 3, 4
d) 2, 3
e) 3, 4
b) 1, 2, 4
115
A stuffing box:
1. stops air leaking into the casing when the pressure is below atmospheric
2. decreases leakage out of the casing when the pressure is above atmospheric
3. is always supplied with a lantern ring
4. is filled with packing
a) 1, 3
b) 1, 4
c) 2, 3
d) 2, 3, 4
e) 1, 2, 4
e) 1, 2, 4
116
Mechanical seals:
1. are used where leakage is objectionable
2. replace stuffing boxes
3. provide a better seal than packing
4. are less costly than stuffing boxes
a) 1, 2
b) 1, 2, 3
c) 2, 3
d) 2, 3, 4
e) 2, 4
b) 1, 2, 3
117
Compression type packing:
1. prevents air from entering the pump
2. reduces the maintenance cost on pumps
3. protects the shaft from scoring and corrosion
4. is used with all mechanical seals
a) 1
b) 2, 3
c) 2, 3, 4
d) 1, 2
e) 1, 3
d) 1, 2
118
Lantern rings:
1. prevent liquid leakage from the pump
2. are fed by a liquid
3. provide a seal to prevent air from entering the pump
4. are mostly used on high lift pumps
a) 1, 2, 3
b) 2, 3
c) 2, 3, 4
d) 3, 4
e) 1, 2
c) 2, 3, 4
119
The seal cage on the shaft of a centrifugal pump:
a) holds the shaft packing against the shoulder of the stuffing box
b) assists in reducing shaft vibration
c) distributes sealing water to the packing
d) prevents water from leaking out of the pump casing
e) reduces suction pressure drop
c) distributes sealing water to the packing
120
The main advantage of a pump using a mechanical seal is:
a) lower first cost
b) less maintenance
c) less lubrication
d) smaller shaft required
e) increases discharge pressure
b) less maintenance
121
A slight leakage is desired between the pump shaft and packing of the majority of pumps in order to:
a) prevent the ingress of atmospheric air
b) increase the pump capacity and efficiency
c) prevent wearing of the wear rings
d) lubricate the surfaces
e) prevent the pump from vapour locking
d) lubricate the surfaces
122
```
If a stuffing box is to prevent the ingress of air, it is
equipped with:
a) a vacuum breaker
b) a seal cage
c) a bushing
d) a thrust collar
e) an anti-air siphon
```
b) a seal cage
123
Any leakage occurring through the surfaces of a mechanical seal will:
a) not be visible to the operator
b) result in an audible sound and be readily noticed
c) be indicated by pump vibrations
d) be axial to the shaft
e) be radial to the shaft
e) be radial to the shaft
124
The component of a mechanical seal which prevents axial leakage is:
a) the seal ring
b) packing
c) the mating ring
d) the O-ring
e) a diaphragm
d) the O-ring
125
What size of packing should you use, to repack a pump gland having the following dimensions: stuffing box bore ------------- 8.6 cm pump shaft diameter ------------- 6.7 cm
a) .5 cm
b) 1.9 cm
c) .675 cm
d) 1.6 cm
e) .95 cm
e) .95 cm
126
New pump packing should be installed:
a) tight enough to stop leakage
b) loose enough to allow leakage for lubrication
c) every shut down
d) every year
e) every time prior to start-up
b) loose enough to allow leakage for lubrication
127
Flexible couplings will compensate for:
a) overheating of packing
b) axial shaft misalignment
c) bearing failure
d) shaft eccentricity due to a badly bent shaft
e) impeller imbalance
b) axial shaft misalignment
128
Shaft misalignment during operation of a pump can be caused by bearing wear, thermal expansion, and
a) shaft flexing
b) throttling of the discharge valve
c) overloading the pump
d) loss of lubricant
e) improper installation
a) shaft flexing******
129
Proper priming and venting of a pump is important, especially if:
a) the medium being pumped is high temperature
b) the medium being pumped contains suspended solids
c) the pump has a stuffing box and lantern ring
d) a mechanical seal is used
e) oil or other low flash point lubricant is being pumped
d) a mechanical seal is used
130
Priming of a centrifugal pump refers to:
a) removal of water from pump
b) filling the pump casing with liquid and removing the air
c) lifting the pump
d) closing the vent on the pump casing
e) starting the pump driver
b) filling the pump casing with liquid and removing the air
131
Priming a water pump means:
a) raising the suction line to the level of the water
b) removing the foot valve to allow the water to flow through
c) closing the discharge valve before starting the motor
d) filling the pumps casing and suction line with water
e) the water is foaming in the pump
d) filling the pumps casing and suction line with water
132
If the packing gland of a centrifugal water pump is leaking too much, you should:
a) tighten up the gland until all leakage has been stopped
b) tighten up the gland but permit a slight amount of leakage
c) tighten up the gland as far as is possible
d) throttle the suction valve a little
e) tighten up the gland until there is 10% leakage
b) tighten up the gland but permit a slight amount of leakage
133
When lubricating equipment, the operator should also check for:
1. unusual machine noises
2. unusual consumption of lubricant
3. excessive heat in bearing housing
4. excessive leakage of lubricant
a) 1, 2, 3
b) 1, 2, 4
c) 2, 3, 4
d) 1, 3, 4
e) 1, 2, 3, 4
e) 1, 2, 3, 4
134
Most pump failures, damage, or both occurs
a) after about six months of continuous service
b) due to vapour-binding
c) during initial start-up
d) due to wrong rotation
e) because of inadequate operator training
c) during initial start-up
135
When a pump is operating, your inspection should include the following:
a) you must check the impeller
b) you must be sure the suction valve is closed
c) you should check the discharge pressure
d) you must be sure the drain valve is open
e) you should check the oil pressure
c) you should check the discharge pressure
136
A plugged impeller symptom or result will be:
a) air leaks in suction line and stuffing boxes
b) wrong direction of rotation
c) loss of prime
d) an overheated stuffing box
e) no liquid being delivered
e) no liquid being delivered
137
If pump speed is too high:
a) the driver may be overloaded
b) discharge pressure will be below normal
c) no liquid will be delivered
d) the pump will lose its prime after starting
e) there will be air or gas in the liquid
a) the driver may be overloaded
138
If a pump is running and has no discharge pressure, what will you do?
a) close the suction valve a little
b) open the lubrication valve
c) check the lubricant level
d) check to see if the suction valve is open
e) close the discharge valve
d) check to see if the suction valve is open
139
You discover that your feed water pump is not delivering sufficient water. A possible cause is
a) the impeller is plugged
b) the suction lift is too low
c) the discharge head is not high enough
d) there is too much water in the pump
e) the foot valve is fully open
a) the impeller is plugged
140
Compressed air machinery would most likely be used in:
a) coal mines
b) residential garages
c) home furnace control systems
d) agricultural applications
e) tool and die shops
a) coal mines
141
Compressed air tools tend to be:
a) heavier than equivalent electrical tools
b) damaged by overloading
c) hot after prolonged operation
d) more expensive than electrical tools
e) less compact than electrical tools
d) more expensive than electrical tools
142
In a centrifugal compressor the kinetic energy is converted to potential energy in the:
a) volute, diffuser, or both
b) intercooler
c) diffuser only
d) compressor cavity
e) volute only
a) volute, diffuser, or both
143
The compressor which would favor volume over pressure would be the:
a) rotary lobe
b) screw
c) axial
d) centrifugal
e) sliding vane
d) centrifugal
144
Positive displacement air compressor types are:
a) centrifugal compressors
b) gear compressors
c) axial compressors
d) multi-stage centrifugal compressors
e) not capable of producing high dicharge pressures
b) gear compressors
145
Single stage reciprocating air compressors:
a) must have an air receiver
b) could be of the rotary type
c) do need an intercooler
d) could have two cylinders
e) have a smooth discharge delivery
d) could have two cylinders
146
A belt driven lubricator is very popular on a:
a) reciprocating double acting unit
b) screw unit
c) rotary lobe unit
d) centrifugal unit
e) sliding vane unit
e) sliding vane unit
147
Higher gearing is commonly used on:
a) rotary lobe units
b) screw units
c) sliding vane units
d) reciprocating units
e) centrifugal units
b) screw units
148
Relative to a dry-pipe fire system, an automatic air supply shall be connected so that proper pressure can be maintained in each system, is a statement of the:
a) National Fire Protection Association Code
b) Industrial Accident Prevention Association
c) Canadian Standards Association
d) Occupational Health and Safety
e) Society of Municipal Fire Marshalls
a) National Fire Protection Association Code
149
In order to protect the driver, a start-stop air compressor should be equipped with:
a) an intercooler
b) an automatic blowdown system
c) safety heads
d) pre-start automatic unloading
e) manual cylinder bleed petcocks
d) pre-start automatic unloading
150
The valves on a reciprocating compressor are opened by:
a) a pressure difference
b) the cam shaft
c) the eccentric
d) hydraulic pressure
e) a timing gear
a) a pressure difference
151
Compressor unloaders:
a) could close the discharge valve
b) must be used on centrifugal compressors
c) could keep the suction valve open
d) activate the stop and start button
e) are located on the driver of the compressor
c) could keep the suction valve open
152
```
Where pistons move in a cylinder it is necessary
for the lubricant to provide
a) tension
b) sealing
c) alignment
d) shock reduction
e) vapour venting
```
b) sealing
153
An air compressor which gives two compression strokes per crankshaft revolution is:
a) multistaged two cylinder
b) multicylinder single acting
c) single cylinder double acting
d) a compound unit
e) single acting
c) single cylinder double acting
154
To reduce air temperature between stages, we would use:
a) an intercooler
b) an aftercooler
c) a receiver
d) a converter
e) a chiller
a) an intercooler
155
An air receiver used in an air compression, system will perform the following functions:
1. act as a storage vessel
2. eliminates pulsation in discharge lines
3. will separate out water from the air
4. controls the temperature of the air before it enters
the system
a) 1, 2
b) 1, 2, 3
c) 1, 2, 4
d) 2, 3, 4
e) 3, 4
b) 1, 2, 3
156
An air compressor auxiliary which will decrease the power requirement is the:
a) receiver
b) diffuser
c) intercooler
d) variable compression ratio head
e) aftercooler
c) intercooler
157
Intercoolers should be equipped with:
a) moisture separators
b) safety valves
c) baffles
d) vents
e) automatic blowdowns
b) safety valves
158
Intercoolers:
a) cool the air in the cylinders
b) are used on all compressors
c) should have a safety valve
d) are required to cool compressor lubricating oil
e) cool the air at the inlet valves
c) should have a safety valve
159
Intercoolers
a) must have a drain
b) are more efficient when cooled with air than with water
c) are used on double acting single stage compressors
d) help increase the volume of the air
e) should use an antifreeze solution
a) must have a drain
160
Air receivers:
a) must have a gage glass
b) must have a thermometer
c) must have a high pressure alarm
d) must have a safety valve
e) must have a high water alarm
d) must have a safety valve
161
Relative to lubrication, one place where wear is beneficial is:
a) new babbit bearing surfaces which wear smooth
b) on pump wear rings
c) on the oil pump sealing surfaces
d) on the cylinder walls of internal combustion engines
e) in antifriction bearings
a) new babbit bearing surfaces which wear smooth
162
The intermeshing of gear teeth is a place where lubrication:
a) corrosion reduction is very important
b) friction reduction is very important
c) sealing is very important
d) shock absorption is very important
e) temperature control is very important
d) shock absorption is very important
163
The lubricant performs a number of functions. Indicate which of the following are the most important:
1. reduce wear
2. temperature control
3. reduce corrosion
4. reduce friction
a) 1, 2
b) 2, 3
c) 1, 3
d) 1, 4
e) 3, 4
d) 1, 4
164
A material which is commonly used as a solid lubricant is:
a) tallow
b) molybdate sulphide
c) lime
d) molybdenum disulphide
e) sodium carbonate
d) molybdenum disulphide
165
Grease is not a suitable lubricant:
a) if the atmosphere contains a lot of moisture
b) when the atmosphere is dusty
c) if corrosion protection is desired during downtime
d) in the food industry
e) if a large amount of cooling is desired
e) if a large amount of cooling is desired
166
A semi-solid lubricant:
a) can only be used for high temperature services
b) has a low viscosity
c) is less likely to drip or splash from bearings
d) has a low pour point
e) is best suited for heat removal
c) is less likely to drip or splash from bearings
167
Lubricant for an anti-friction bearing is:
a) mineral oil
b) graphite
c) calcium or lime base grease
d) not required
e) barium and lithium base grease
e) barium and lithium base grease
168
Which type of grease is the cheapest and most commonly used?
a) lithium base
b) teflon base
c) paraffin base
d) calcium base
e) silicon base
d) calcium base
169
The property of an oil which indicates its ability to support a load is:
a) viscosity
b) viscosity index
c) pour point
d) floc point
e) consistency
a) viscosity
170
If an oil's viscosity changes much with little temperature change then it will have a:
a) low viscosity index
b) high pour point
c) high carbon residue
d) high viscosity index
e) low pour point
a) low viscosity index
171
```
Which of the following has the greatest effect on
the viscosity of a lubrication oil?
a) pressure
b) load
c) flow
d) temperature
e) speed
```
d) temperature
172
```
The resistance of a liquid to internal deformation
or shear is known as:
a) pour point
b) viscosity index
c) flash point
d) viscosity
e) friction resistance
```
d) viscosity
173
Which type of oil produces higher fluid friction?
a) a high viscosity oil
b) a low viscosity oil
c) a low viscosity oil with a high flash point
d) synthetic oils
e) all mineral oils
a) a high viscosity oil
174
Oil additives:
a) should not affect all other characteristics greatly
b) will always affect the pour point greatly
c) should be used as little as possible
d) are not a component of most lube oils
e) never lose their effect during use of the oil
a) should not affect all other characteristics greatly
175
If you desire an oil to flow at a much lower temperature you would most likely add:
a) a viscosity index improver
b) pour point depressants
c) a dispersant
d) a thickening agent
e) low viscosity oil
b) pour point depressants
176
High capacity steam turbine oils should:
a) have a low specific heat
b) have a very high viscosity
c) be fire resistant
d) have a low pour point
e) mix well with water
c) be fire resistant
177
Air compressor oil should:
a) have a very low viscosity
b) have low carbon residue
c) have a low flash point
d) not contain anti-oxidants
e) have high shock absorption characteristics
b) have low carbon residue
178
High viscosity oils are normally used for the following applications:
a) low speed, high load
b) low speed, low pressure
c) high speed, high load
d) high speed, low temperature
e) high temperature, low load
a) low speed, high load
179
A lubricant characteristic which will indicate its ability to support a heavy load at low speed is:
a) viscosity index
b) pour point
c) viscosity
d) density
e) relative density
c) viscosity
180
A form of lubrication which requires continual motion of a shaft or surface is:
a) boundary lubrication
b) alemite fitting lubrication
c) forced lubrication
d) zerk fitting lubrication
e) fluid film lubrication
e) fluid film lubrication
181
Fluid film lubrication:
a) is used for heavy loads
b) removes all friction in the bearing
c) is used on all anti-friction bearings
d) is used only during low ambient temperature conditions
e) is used for light loads
a) is used for heavy loads
182
Fluid film lubrication:
a) is always used with a high viscosity oil
b) is also called flood lubrication
c) is always used with a grease lubricant
d) is different from flood lubrication
e) does not separate the metal surfaces
b) is also called flood lubrication
183
```
In a forced lubrication system, a pump supplies oil
_________________ for the bearings.
a) by gravity
b) to an oil sump
c) to a drip feeder
d) to a wetted wick
e) under pressure
```
e) under pressure
184
Large journal or sleeve bearings have grooves:
a) in the high pressure area of the bearing babbit
b) cut into the bearing housing
c) for distributing lubricant evenly just after the pressure area
d) in the non-pressure area
e) cut in them for cooling purposes
d) in the non-pressure area
185
A large journal bearing which is running hotter than normal can be cooled by:
a) direct application of cool water
b) loosening the bearing caps
c) decreasing the viscosity of the oil by cooling it
d) adding pour point depressant to the oil
e) using CO vapour
b) loosening the bearing caps
186
```
A thrust bearing which does not utilize the oil wedge
principle of lubrication is the:
a) Michell type
b) collar type
c) flotation type
d) Kingsbury type
e) vertical type
```
b) collar type
187
```
One of the main functions of the lubricant in a sealed,
grease type antifriction bearing is:
a) wear reduction
b) sealing
c) shock absorption
d) cooling
e) surface separation
```
b) sealing
188
A journal bearing:
a) controls thrust movement
b) does not require lubrication
c) improves suction pressure
d) does not require a housing
e) supports a shaft
e) supports a shaft
189
Thrust bearings:
1. are used on reaction turbines
2. prevent the turbine rotor moving axially
3. are always installed on both ends of the rotor shaft
4. are lubricated with the same oil as the main bearings
b) 2, 3, 4
c) 1, 2, 3
d) 1, 3, 4
e) 1, 2, 3, 4
a) 1, 2, 4
190
The lubricant for an anti-friction bearing:
a) will separate the moving parts completely
b) must be cooled
c) could be a semi-solid lubricant
d) prevents axial trust
e) should have a high viscosity
c) could be a semi-solid lubricant
191
```
A collar thrust bearing:
1. can support more load than a Michell thrust bearing
2. can prevent a rotating shaft from moving both axial
directions
3. has boundary lubrication
4. is an anti-friction type bearing
a) 1, 2
b) 2, 3
c) 1, 2, 4
d) 1, 2, 3, 4
e) 3, 4
```
b) 2, 3
192
A thrust bearing:
a) prevents radial movement of the shaft
b) prevents axial movement of the shaft
c) must be installed on both ends of the shaft
d) has a volute casing
e) should rotate opposite to the shaft
b) prevents axial movement of the shaft
193
An anti-friction bearing:
a) could be a thrust bearing
b) is a bearing containing white-metal alloy
c) is a sleeve bearing
d) receives larger amounts of oil
e) cannot operate in an oil bath
a) could be a thrust bearing
194
A collar thrust bearing:
a) must have a shiny surface
b) can support more load than a michell thrust bearing
c) is an anti-friction type bearing
d) is used with steam turbines only
e) has boundary lubrication
e) has boundary lubrication
195
A type of anti-friction bearing is the __________ bearing.
a) spiral
b) elliptical
c) ball
d) sleeve
e) journal
c) ball
196
Using pressurized air to blow out a cleaned bearing:
a) should only be done when ventilation is maximum
b) must be done only while the bearing is hot
c) will cause the bearing to become "pitted"
d) requires high pressure air
e) can not cause damage to or affect our skin in any way
c) will cause the bearing to become "pitted"
197
When replacing or removing an antifriction ball bearing, the applied force should:
a) not be transmitted through the bearing balls
b) always be against the inner race
c) always be against the outer race
d) be applied suddenly and fully
e) be made only after heating the bearing
a) not be transmitted through the bearing balls
198
Applying installation forces through the balls of a bearing can cause:
a) bearing misalignment
b) false brinelling
c) cracking or breaking of the balls
d) improper lubrication
e) brinelling
e) brinelling
199
A normal antifriction bearing temperature operating range is:
a) 150 to 160 degrees C
b) 120 to 250 degrees C
c) 20 to 50 degrees C
d) 65 to 70 degrees C
e) 80 to 120 degrees C
d) 65 to 70 degrees C
200
When grease is used in an antifriction bearing, the bearinghousing should not be filled more than __________ full.
a) 1/4
b) 1/3
c) 1/2
d) 3/4
e) completely
b) 1/3
201
Causes of anti-friction bearing failures are:
1. improper fitting
2. false brinelling
3. high operating temperature
4. poor quality lubricant
a) 1, 3, 4
b) 2, 3, 4
c) 1, 2, 3
d) 1, 2, 3, 4
e) 3, 4
d) 1, 2, 3, 4
202
What do you look for before starting a pump?
a) For free rotation of the lantern ring
b) That the packing is drip free
c) Leakage around the pump
d) Be sure that the area around the pump is cool and dry
e) The position that the suction and discharge valve are in
e) The position that the suction and discharge valve are in
203
When the supply is above the pump the total static head of the pump will be the:
Difference between the static suction head and the static discharge head
204
Intercoolers
Must have a safety valve when used on positive displacement
205
When inspecting a dismantled bearing, the first indication of a failing bearing is:
Roughness
206
The name given to a pump that uses gear teeth, vane, lobes, or screws to move the fluid being pumped is the ----------type
Rotary
207
The liquid to a lantern ring:
Keeps the air out of the pump
208
The point at which oil will give off enough vapor to ignite and burn continuously, is known as the --------point
Fire
209
The area around a pump shaft, where packing material is placed to reduce leakage around a shaft, is known as:
a) Seal box
b) Stuffing box
c) Gear box
d) Casing flange
e) Wearing ring
b) Stuffing box
210
In a bearing, the lubricant reduces the heat produced by
b) Friction reduction
211
The purpose of "wear rings" in centrifugal pumps is to:
a) Prevent wear on the pump inlet
b) Prevent wear at the pump discharge
c) Lower the pump pressure
d) Eliminate the need for a relief valve
e) Increase the efficiency
e) Increase the efficiency
212
Centrifugal pumps do not develop good suction lift because:
a) Atmospheric pressure is usually too low
b) Their internal component clearances are too high
c) The pumped medium relative density is too high
d) They favor pressure rather than volume
e) The speed is too low
b) Their internal component clearances are too high
213
The proper way to store a bearing after cleaning is to dip it in a ________ preventative and wrap it inb grease-proof paper
a) Rust
b) Moisture
c) Chemical
d) Air
e) Gas
a) Rust
214
After a bearing has been removed for cleaning, it should be soaked for a period of _______ hours
a) 12 to 16
215
Sliding vane compressors
a) Fall into the centrifugal compressors category
b) Are positive displacement compressors
c) Are 100% efficient
d) Use cylinder valves
e) Are double acting compressors
b) Are positive displacement compressors
216
If a lubricating oil has a high viscosity index number, this means the viscosity will:
a) Vaporize with a temperature increase
b) Change a great deal with temperature change
c) Not change at all with temperature change
d) Change little with temperature change
e) Increase in pressure as the temperature decreases
d) Change little with temperature change
217
The purpose of a shaft sealing on a pump is to:
a) Stops fluids from leaking along the pump shaft
b) Keep the packing gland cool
c) Protect the seal
d) Keep air in the pump
e) Prevent lubricating oil from leaving the pump
a) Stops fluids from leaking along the pump shaft
218
The kind of grease used for heavily loaded machinery operating at slow speeds is the:
a) Sodium base grease
b) Calcium base grease
c) Mixed base grease
d) Specialty grease
e) Acid base grease
d) Specialty grease
219
The majority of lubricants are:
A) Mineral oils
B) Synthetic oils
C) Animal fats
D) Greases
A) Mineral oils
