8th Six Months Flashcards
You can control chain tension by changing shaft centers or using a?
Idler sprocket
A roller chain should be allowed to sag ___ percent of the distance between sprocket centers.
About 2
- In chain operations, the areas of greatest load are the?
Chain joints
You should make your first full-scale inspection of a new drive chain after ____ hours of operation?
24
Chain side plates that show signs of uneven wear usually indicate that the?
Drive is misaligned
In a vertical chain drive without an idler the shafts should be installed at an angle of no more than?
60°
The most common cause of drive chain failure is?
Improper lubrication
Which of the following describes the type III lubrication method?
Splash
- A scraping or slapping noise during a test run of a chain drive may indicate that?
The chain is striking something
Before using chain that has been stored on open reels you should?
Clean it with solvent
After mounting sheaves and pulleys, you should check their alignment with a?
Straight edge
The best way to tighten a V-belt that has stretched is to?
Adjustable center distance between sheaves
A splice commonly used on low-speed flat belts is the ___ splice?
Stepped
. If a new flat belt is running well, how long should you test run it under normal load?
48 hours
- A burned spot on a belt probably indicates?
Belt is overloaded
Which type of belt is installed on sheaves rather than on pulleys?
V belt
If a v-belt in a multi belt drive shows wear you should?
Replace the full set of belts
Which of the following is the correct way to check a V-belts tension?
Apply a specific amount of force to the top side of the belt
Which of the following is the best way to take up slack in a flat belt?
Adjust the center distance
The pulleys for a positive drive belt have a?
Flange on each side
Which of the following drives permits practically no misalignment of the shafts?
Gear
The critical dimension that ensures accurate meshing of a worm and worm gear is its?
Distance between the centers
When mounting spur or helical gears that have only one hub, you should position the hub?
Away from the bearing
When cracked or broken areas appear on teeth that are almost new, the cause is probably a?
Foreign object
If the metal at the tips and roots of gear teeth has been gouged or worn, the cause is probably?
Too tight a fit between gears
Which of the following happens to open gearing during the run in period?
Gear polish up
The DP of a gear is the ratio of the number of teeth to the ____ in inches.
Pitch diameter
Which of the following is used to check gear alignment after installation?
Steel square
What should you do if spalling occurs in an open gear drive?
Gear treat the teeth
Which of the following is the best solution for gearing with cracked rims?
Replace the gear
When installing an enclosed gear drive on the floor you should mount the feet on the?
Steel base pads
What components of an enclosed gear drive prevents the buildup of pressure or the formation of a vacuum inside the drive housing?
Breather
If an enclosed gear drive is to be stored in the plant for a long time, you should?
Fill the drive completely with oil
Most unusual noises that develop after an enclosed gear drive has run a while originate in the?
Shaft bearings
What does discoloration of worm gear teeth indicate?
Burning by overloading
Which tool is used to check the levelness of an enclosed gear drive on its foundation?
Spirit level
Which is the most common method of lubrication for bearings on enclosed gear drives?
Splash
During the run in period you should run the drive system at half load for __ to ___hours.
8-10
After a gear drives first week of operation under full load you should?
Check the oil level
Which of the following is found on the nameplate of an enclosed gear drive?
Load capacity
Which elements of the drive package should you move to set the coupling gap?
Motor
What instrument is used when very precise coupling alignments must be made?
Dial indicator
What instrument is used when very precise coupling alignments must be made?
Dial indicator
A floating shaft coupling should be used when the?
Drives exert axial thrust
If the power requirements of a driven machine have been changed so that over-loading occurs you can solve the problem by installing the?
Next larger coupling
A coupling can serve all of the following purposes except?
Insulate against high temperatures
The gap between spacer couplings and the hubs should be ___ inches?
0
What is the usual cause of whipping on a floating shaft?
Excessive misalignment
An uneven wear pattern on a gear type coupling is usually a sign of?
Misalignment
The slack in the fit between coupling components is known as?
Backlash
The most common cause of failure in jaw clutches is?
Jaw breakage
V-belt sheaves, shafts and gears can all be used as?
Takeoff members
Localized wear on clutch friction surfaces often indicates?
Misalignment
Frequent slippage of a brake or clutch is usually an indication of?
Overloading
Chatter is usually caused by?
Loose or faulty actuating devices
Friction clutches use one or more discs to?
Transmit torque to the load
Rapid wear between the friction surfaces by an electric brake or clutch is usually the result of?
Overheating
When the slip speed of a clutch drops to zero, the maximum torque of the clutch can exert?
Increases
The capacity of a clutch to dissipate heat depends on its size and?
Armature speed
If a brake or clutch fails to engage properly, the first thing to check is the?
Voltage supply to the coil
At _____ output speed, the flanges on the input shaft of an adjustable-speed drive are?
Maximum; closest together
The best protection against unwanted heat in a an enclosed drive is a?
Steel baffle
When test running and adjustable speed drive under no-load conditions, it is necessary to operated the drive?
Through its full speed range
If you find ridges in a drives sheave flanges on an adjustable speed drive you should?
Sand or polish the ridges away
In an enclosed drive, high temperatures usually result from a?
Overloading the shaft bearing
The amount of slip between a turbine and its impeller is normally a difference of ____ to ____ percent at full load.
3 to 5
A condition called a “stall load” can occur in a fluid coupling when the impeller _____ and the turbine ______?
Rotates; does not rotate
Over heating in a fluid coupling is usually caused by ?
Too much slip
A polyphase torque converter has _____ stators that _____?
Two or more; rotate
If you find seals that are hard and cracked when you are inspecting a coupling, you should ?
Replace them
An enclosed gear drive thermal capacity is usually expressed in?
Horsepower
When you need to change the speed of a load shaft you should select a drive with a?
Adjustable speed belt
The major cause of drive failure is?
Improper lubrication
If an overload occurs in a drive system that is equipped with a spring-operated overload device the?
Sprocket will slip
When test running a drive prior to placing it in service, you should run the drive under no-load conditions for?
20-30 minutes
Which of the following diagrams represents the proper sequence for tightening hold-down bolts when installing an enclosed adjustable speed drive?
C
1 3
2 4
The best way to determine the correct running clearance in a plain-bearing is to?
Consult manufacturers charts and tables
The ability of bearing material to dissipate excessive heat generated during operation is called?
Thermal conductivity
The ability of bearing material to flow slightly when loaded is called?
Conformability
An advantage of grease compared to oil in lubricating a plain bearing is that?
Newly applied grease forced old lubricants out
Discoloration in plain bearings is generally a symptom of?
Excessive heat
Which of the following should be used to measure the running clearance of a plain bearing?
Feeler gauge
Which method should be used to remove moisture from a bearing shell after it has been cleaned?
Preheating
When building a plain bearing liner, coat the mandrel with ___ to keep molten Babbitt from clinging.
White lead
What is the purpose of the grooves cut onto a plain bearing liner?
Circulate lubricant
Which is the most likely cause of screeching from a plain bearing during operation?
Clearances are too tight
If you must leave your workplace temporarily, what care should you give a new, unmounted antifriction bearing?
Wrap it in oil resistant paper
. To prevent creeping of an inner bearing ring around the shaft, you should mount the inner ring with an ___ fit.
Interference
You can force an antifriction bearing into position on the shaft by using an arbor press or by impact, if the bearing has an O.D. of?
4 inches or less
A bearing is driven up a split tapered adapter by?
Tightening a heavy duty locknut
At approximately what temperature should you begin to suspect a bearing problem?
At approximately 185°F
You clean an antifriction bearing before installation if it?
It will be lubricated by automatic oil mist
If the shoulder is too low when seating an antifriction bearing on the shaft the?
Inner ring may distort
When inspecting a tapered shaft by blueing the gauge bore, a ___ % blueing transfer is acceptable?
80%
When cold mounting an antifriction bearing, you must?
Lubricate the bearing bore and shaft with light oil
Which of the following is not an approved way to heat a roller bearing for a temperature mount?
Gas operated torch
What is the correct tool to use when removing a locknut from an antifriction bearing installation?
Spanner wrench
When you use a puller to remove a taper-mounted bearing, what should you do with the locknut?
Back the nut off several turns
An aluminum heating ring is designed for mounting and dismounting the inner rings of a ___ bearing.
Cylindrical roller
When you use an aluminum heating ring to expand a bearing, heat the ring to?
500°F
If you have cleaned and inspected an antifriction bearing but do not intend to reuse it immediately, how should you treat it before wrapping it in oil-resistant paper and storing it?
Fill it with grease
The two main methods of removing antifriction bearings are?
Impact and heating
Which of the following is a correct way to remove an antifriction bearing with a diameter smaller than 4 inch?
Arbor press
The two important dimensions of a bearing puller are spread and?
Reach
To remove a bearing, a splitter may be used with a?
Mechanical puller
Which of the following should not be used to clean an antifriction bearing when inspecting it?
Steam
Which type of bearing seal keeps out water, dirt, and contaminants most effectively?
Contact seal
Which type of antifriction bearing can tolerate the most internal misalignment?
Spherical roller bearing
The correct tolerance range for shafts from 2 to 4 inches in diameter is nominal to?
-.001 inches
When you lubricate bearings with grease, the actual lubricant is ___, which is held in suspension.
Mineral oil
As a rule, the interval between lubrication renewals is cut in half for every 27 degrees Fahrenheit increase in temperature above?
160°F
. A special type of pillow block sometimes used on belt conveyors is called a?
Takeup
When using the grub screw method to hold a bearing in a pillow block, use?
No collar
To find the takeout amount needed to calculate final clearance when installing a bearing, refer to the?
Manufacturers chart
Which type of lubricant increases the effectiveness of a labyrinth seal?
Grease
Bearing temperature is typically ___ to ___ degrees Fahrenheit higher than the temperature of the housing.
15° to 25°
The threads of an acme screw are?
Squared off & thick
Ball bearing screws are designed to?
Move loads vertically and horizontally
The screw in a ball bearing screw is supported by?
Standard ball bearings
. In a contact seal, what forms the actual seal?
A thin film of oil
Before you install a lip seal, chamfer the end of the shaft and the leading edge of the housing bore at an angle of ___ to ___ degrees.
15 to 30
The rolling contact of a ball bearing screw is ___ % efficient.
90%
Which of the following carries the load moved by a ball bearing screw?
Ways
When preparing a ball bearing screw for installation, use a ___ to expand the inner ring of the bearings.
Hot oil bath
Which seal is most effective when large quantities of contaminants are present close to the machinery?
V-ring
Which seal material works well for machines operating at extremely low temperatures?
Silicone
1 The two units of measuring liquid pressure are?
P.S.I ; Foot of head
The available NPSH of a system should be _____ the required NPSH of the pump.
Equal to or greater than
The formation of vapor pocket or bubbles within a liquid id called?
Cavitation
The horsepower required to actually drive a fluid-handling pump is called the?
Brake hp
One electrical horsepower equal ____ watts.
746
The area that surrounds and houses the packing in a pump is called the?
Stuffing box
When installing four or more packing rings, you should stagger the joints ____ degrees apart?
90
The most common mechanical seal configuration is the ____seal?
Single internal
9 In some mechanical seals, the rotating element is secured to the shaft by a?
Boot
The major cause of burned seals is?
Improper lubrication
After grouting a baseplate, you should allow the grouting mixture to set for at least?
48 hours
When removing springs from pump feet, you should measure movement with a?
Dial indicator
Unwanted movement of a pump shaft along its axis is called?
End play
Cavitation is caused by
Pressure loss
Loss of clearance between wearing rings is called?
Ring seizure
On a pump that has both bearings on the same side of the impeller, the bearing nearest the impeller is called the ______ bearing?
Inboard
The most common sign of cavitation in a pump impeller is?
Putting on the back side of the vanes
In general, runout on a pump shaft should not exceed ____ inches.
.003
Too much clearance between the stationary rings and the impeller or rotating rings of a centrifugal pump will cause?
Fluid leakage
When installing a new gasket, you may wish to apply ____ to the lower half of the casing.
Shellac
The most commonly used type of all rotary pumps is the ______ pump.
External gear
In a vane-type rotary pump, what keeps the sliding vanes in contact with the pump housing?
Centrifugal force
The riser used to vent a system at the discharge side of the pump should be about _______ times as long as the diameter of the pipe?
5
Internal bearings on rotary pumps are most often lubricated by?
The fluid being pumped
If a rotary pump is not delivering fluid at its discharge side, the first thing you should do is?
Stop the pump
- Which method is used to measure a pipe with a fitting at one end?
End to center
Which of the following displayed symbols describes a flanged tee?
=
—||—-|—–||–
Which type of flange is used to seal the end of a pipe?
Blind
Given a 45 degree offset shown with a 41 inch travel a center to face elbow dimension of 2 inch and a ¾ inch length, what is the end to end pipe length?
38.5 inches
Straight internal pipe threads in pipe couplings are represented by the code letters?
Npsc
. In complete pipe specifications, code letters are preceded by two numbers which indicate the?
Nominal pipe size and number of threads per inch
The distance from a given point on one pipe thread to the same point on the next thread, measured parallel to the pipe centerline, is called the?
Pitch
You need to replace a threaded pipe between 45 degree elbows in a straight offset. The set is 5 ft, and the travel is 7.07 ft. The center-to-face dimension of each 45 elbow is 2 in., and the pipes thread length is 3/4 in. The total end-to-end length of the replacement pipe is?
82.34 inches
Ratchet threaders can be used on pipe up to about ____ inch in diameter.
6
Socket-welding fittings are used for joining pipe of what diameters?
4 inches or less
Backing rings should always be made of?
Material compatible with the pipe material
Squareness is a term indicating that a pipe forms a _____ angle with another.
90 degree
The major assembly consideration when fabricating flanged connections for a rolling offset is?
Aligning the holes
The usual gap between pieces of pipe to be butt welded is approximately?
3/16 inch
A major advantage of thermoplastic pipe is that?
It is highly resistant to corrosion
Which of the following is a fiberglass-reinforced thermosetting pipe material?
RTRP
The solvent cement used to install fittings on thermoplastic pipe requires _____ hours to cure completely
1/2 to 4 hours
When installing threaded fittings on plastic pipe, you should tighten the joint by hand or with a?
Strap wrench
To ensure a good bond when installing bell fittings on thermosetting pipe, the ends of the pipes should be?
Lightly sanded
What kind of hanger is used if a rigid hanger would swing more than 4 degrees?
Roller
A steam trap is a pipefitting accessory that removes?
Condensate
Steam traps should he installed at the ______ point in the system.
Lowest
Which of the following fixtures is used to remove very small particles from a piping system?
Filter
What kind of expansion joints can be used where temperature changes cause axial pipe movements?
Slip and bellow joints
Water is usually carried in ______ tubing; If it is under high pressure, _____ tubing is usually used.
Copper; stainless steel
A flareless compression fitting is one that?
Bites into tubing
Annealing is sometimes necessary to make tubing?
Easier to bend
When you use a cutter to cut tubing, the cutter should _____ and the tubing should ___?
Rotate; not rotate
To get the most accurate measurement of required tubing length, you must measure along the path of the tubes?
Centerline
The tensile strength of tubing is based on the ______ and the ______?
Tubing material; wall thickness
How does increasing the operating temperature affect the strength of tubing?
Decreases it
What type of fitting is commonly used on tubing that carries a flammable liquid or gas?
Flared
What is the first step in installing a flared fitting?
Slide the nut over the tube
What is the most common cause of leaks in a tubing system?
Poor fitting connection
What is the most frequently used hydraulic fluid?
Oil
What device is commonly used to keep hydraulic systems from building up excess pressure?
Relief valve
What type of fittings should be used with copper tubing in hydraulic systems?
Brass
If the pump in a hydraulic system is noisy, the most likely cause is a?
Insufficient fluid supply
Contaminated fluid in a hydraulic system often causes?
Fluctuating pressure
A typical multipurpose industrial hose can carry saturated steam at pressures of up to?
150psi
A shaft that serves to support a fitting during assembly is called a?
Mandrel
The most common method of attaching reusable fittings to hose is?
Threading
Calculate the required hose length if a 40 degree bend is to be made in a hose and the radius of the bend is 8 in.
5.58 inches
Hydrostatic tests of a hose system should be conducted at ___ percent of the recommended working pressure of the hose?
150
The most important dimension of a gasket from a total performance standpoint, is its?
Thickness
The electrical signal generated by a profilometer is converted into a reading displayed in?
RMS
Waviness in flange surfaces is usually expressed in _____ of an inch.
Thousandths
Waviness in flange surfaces is usually expressed in _____ of an inch.
Thousandths
Coatings serve to reinforce a joint seal and keep the gasket from?
Creeping
TFE-based gasket strips can accommodate operating temperatures of up to?
250°F
Which of the following valve materials is the best choice for service conditions that include high pressures, high temperatures, and corrosive fluid?
Stainless steel
. If a valve must be removed frequently for service or repair, the valve-to-pipe connection should be?
Threaded
The first step in stopping leakage around the stuffing box of a gate valve is to?
Tighten the gland bolt nuts
If the stem of a globe valve does not move freely, one likely cause is a?
Damage spot on the thread
What is usually the first indication of a valve problem?
Leakage
The first part of a diaphragm valve to wear out it usually?
The diaphragm
What causes a pop safety valve to open?
Pressure rising above a preset value
For most pop safety valve, pressure and temperature are usually limited to?
250-450psi
Chatter in pop safety valves is caused by a _____ volume of flow at a ____ pressure.
Low;high
What part of a safety relief valve contains the pressure that opens the valve?
A huddling chamber
A mechanism used to open or close a valve is called a?
Actuator
The maximum air pressure for pneumatic diaphragm actuators is approximately?
125psig
Which of the following devices is used to measure fluid pressure?
Bourdon tube gauge
Which of the following indicates flow rate by producing an electrical signal?
Turbine flow meter
Accumulators are used for?
Storing pressure
Applications that call for fully open or fully closed positions are best handled by a ____ valve.
Gate
The valve best suited for regulating flow is the ______ valve.
Angle
Which of the following valve materials is most best for use in high-pressure, high temperature conditions?
Steel
The marking “WOG” on the body of a valve stands for?
Cold water, oil, and gas
. Flanged joints require the use of ______ to create an effective seal?
Gaskets
One of the most common signs of insulation failure in steam lines is?
Leakage
Condensate in a steam tracing system should be drained to the?
Collection header
One of the disadvantages of electric tracers is that they?
Require constant monitoring
. The simplest way to protect an exposed water line from freezing is to?
Drain the line
Which of the following is an example of passive corrosion protection?
Installing a pipe liner
The machine operator frequently can give the troubleshooter?
Valuable information
Mechanical, hydraulic, and pneumatic systems all are worked on by the?
Mechanical troubleshooter
The purpose of good maintenance is to?
Keep machines and equipment working
A maintenance specialist reports to craft supervisors in all plant departments in a plant organized under?
Central organization
In a large plant, the building maintenance group is most likely to be made up of?
Electricians, Mechanics, Plumbers, Carpenters, and Painters
All communications is essentially a cycle of ____ steps.
Four
When you give a person a chance to express himself, you may?
Find him easier to work with
Writing down an order?
Helps prevent misunderstandings
Before you make a repair, you should?
Find out what your responsibilities are
If you have a problem or complaint about your job, you should?
Report it directly to the supervisor
If possible, you should schedule repair work for a time when?
The machine is not in use
Before you can diagnose problems, you must ?
Be able to recognize Normal operations
An ohmmeter measures?
Resistance
Air supplies should be checked?
When the machine is running
Your first duty in an emergency is to?
Protect workers from injuries
When should the troubleshooter check the machine drawings in the service manual?
Before working on the machine
Parts lists do NOT
Include a great deal of written technical information
High values of resistance can be measured with a?
Megohmeter
A bourdon tube is used to measure?
Pressure
Which of the following instruments measures the difference between two temperatures?
Thermocouple
The tools in your toolbox do NOT need to be?
New
When should you remove your lock from the machine controls?
After you have replaced the machine guards and covers
To recheck a system after making a repair, you should?
Run the system under both automatic and manual controls
Drive chains that run at speed of over 500 feet per minute require?
Constant lubrication
Which of the following conditions indicated conveyor overload?
Uneven spaces between the top plates of the conveyor chain
The diagram that shows both the external shape and the internal working parts of a system or a component is a?
Cutaway diagram
A piping system is shown in three dimensions in a?
Isometric diagram
A wiring diagram shows the?
Physical relationships of devices in an electrical system
Which of the following is used to trace the wiring in the ceilings and walls of a building?
Lighting diagram
Step-by-step instructions for testing equipment are included in a?
Troubleshooting chart
Modern precision-built bearings?
Help support power transmission shafts
Side-to-side movement of a shaft in a sleeve bearing should be no more than?
Two thousandths of an inch
NOT all centrifugal compressors have?
More than one air supply
Centrifugal, wet, and bag are types of?
Mechanical dust collectors
Synthetic coatings greatly improve the strength and resistance of a?
Floor
Electrical switchgear consists of?
Equipment that controls, protects, and regulates machinery
A panelboard is a small assembly that contains?
Either fuses or circuit breakers
Which type of diagram shows the parts of a circuit as they actually appear to the eye?
Pictorial
The basic unit for measuring electric current is the?
Ampere
Potential difference is measured with a?
Voltmeter
In a normal work-order procedure, which of the following jobs is done by the scheduler?
Issues the work order
Determining what parts and supplies are needed to make an emergency repair is the job of the?
Emergency crew
The best approach for identifying the cause of a breakdown in automatic machinery is?
The systematic one
The decision to run a machine part to the point of breakdown must be made?
Very carefully
Wear to machine parts caused by contact with chemically active materials is an example of?
Corrosion
The inspection and repair of plant equipment at regular intervals is called?
Planned maintenance
The work order form is used for?
Issuing instructions and obtaining feedback
Which of the following machine parts require daily lubrication?
Shafts and bearings
All of the following will cause a drive belt to deteriorate EXCEPT?
Too much ventilation
The sag in a drive chain should be about 1/4 in. for every ______ in. of distance.
12
The rotating weight of the unit is transferred through the trust bearing, though the upper bridge, and trough the _______ to the foundation.
Stator frame
On an umbrella unit, the thrust bearing is located?
Below the rotor
The three types of thrust bearings are?
Adjustable shoe, self equalizing and spring loaded
The adjustable shoe thrust bearing uses a ______ under each of the shoes for adjusting the height and loading of the shoes.
Jack screw
To install the thrust block, it is heated to a predetermined temperature and lowered over the shaft, again with the unit on jacks. The block is set on the _____. The rigging removed, and the radial keys and the keeper installed.
Thrust shoe
With the thrust block still hot and installed on the shaft, the jacks are released to?
Allow the full weight of the unit to set the block in place against the keys
Using the thrust bearing high pressure lubrication system, allows for both ____ and ____ movement required during the alignment process.
Rotational; lateral
As alignment deviates, loading on the guide bearings will increase a will ____ levels.
Vibration
Any increase in vibration from misalignment will decrease the ___ factor of operation in severe circumstances.
Safety
The concentricity of the stationary components can be checked by?
Hanging a single tight wire to check plumb reference
The tolerance for plumb center of shaft runout is ____ multiplied by the length of the shaft from the highest plumb reading to the lowest plumb reading in inches.
0.000025
The tolerance for shaft straightness should not be more than ____ inch from a straight line connecting the top and bottom reading point.
.003
The parallel misalignment between two shafts that occurs at the coupling between the generator and turbine shaft is called?
Offset
Shaft dogleg is?
Angular misalignment of the turbine and generator shafts
Plumb wires should be hung _______ apart.
90°
The first preliminary check during the alignment process, it to loosen the mounting bolts on each leg of the upper bridge to check for?
Soft foot
One of the most important things to check before taking alignment readings is to make sure the?
Shaft is free
The procedure that is particularly useful during major overhauls is to temporarily install the upper and lower bridges and the head cover to check the concentricity of the stationary components with a single plumb wire and a?
Electric micrometer
When the unit is centered the concentricity can be checked by taking _____ readings at the turbine guide bearings, seal rings, generator air gap, etc.
Clearance
Correcting dogleg between the generator and turbine shafts requires installing a shim pack between the?
Coupling faces
The second method used for aligning Hydrounits with adjustable shoe thrust bearings is using the adjustable feature of the shoes only to achieve equal?
Loading
On self equalizing thrust bearings, one step in the procedure is to center the shaft in the ________ housing and move the ______ of the shaft to make plumb.
Turbine bearing; top
The final step in the alignment process is the installation and adjustment of the?
Guide bearings
To make the generator guide bearings concentric to the turbine guide bearing, the _____ is used as a reference.
Shaft
When installing the turbine bearing, several ____ are used to prevent lateral movement.
Dowels
Although vertical hydrounit machines may be extremely large?
Close tolerances must be maintained
The vertical hydrounit machine that has the thrust bearing and upper guide bearing located above the rotor is called?
Suspended type
On large low-speed vertical hydrounit machines, the rotor poles are secured to the rim by?
Driven tapered keys
On an adjustable blade pump or propeller (kaplan) type turbine, a hollow shaft is required on the electrical machine to?
Allow oil pipes to be carried through the shaft from the oil head at the top of the unit to The turbine servomotor
On guide bearings, lubrication arrangements eliminate the need for an oil circulating system. The designated oil level is usually about ____ the length of the bearing above its lower end.
1/3
Brakes are usually operated by compressed air at ____ psi. When used as jacks, the brakes are operated by an oil pressure of ______psi.
75-100; 1000-3500
High pressure bearing lubrication is frequently used to reduce?
Break away Torque
The high pressure bearing lubrication pump assembly uses a _____ to prevent starting the machine (hydrounit) until the pressure is approximately 1000 psi.
Pressure switch
Prior to erection of the unit, the turbine or pump runner and shaft are centered and supported in a position at a specified distance usually ________inch below the correct operating position.
1/4 to 3/4
During the alignment process, fins should be provided on the plumb bob to allow it to hang in a pail of heavy oil to dampen any swings and protect the plumb line from?
All strong air currents
Electric welding on any part of the machine is a serious hazard to bearings. A bearing surface can be damaged?
Rapidly if welding current passes through it
In regards to hydrounits, if possible all electric welding should be done?
Before bearings are assembled
The thrust bearing tub cooling coil should be water-tightness tested to a water pressure of _______% of normal working pressure.
150
Precautions should be taken during assembly of the thrust bearings to avoid?
A.T.A.
Segmental bearings made up of independently adjustable segments must be set to?
Proper elevation and clearance
To eliminate the possibility of shaft current, bearings and other parts should be?
Insulated
Check the insulation with a _____ volt insulation meter, if the resistance is less thank ____ohms inspect the insulation and make necessary corrections
500; 20,000
Before drawing the couplings together, their mating surfaces must be in alignment, parallel, clean and free from burrs. The coupling must be drawn up?
Evenly to prevent distortion
Coupling bolt tension can be determined by an accurate measurement of the bolt?
Elongation
To prevent plumb wires from swaying and twisting, the finned weights should be immersed in pails of?
Oil
Check commutator _____ with a dial indicator rather than by visual observation.
Runout
Various instruments and relays and their associated equipment, wiring, piping and conduit should be carefully installed, making sure that it does?
No short Circuit the
bearing insulation
The rotating parts of the machine must be in ____ balance and may require the addition of weights to the rotor.
Dynamic
Before connecting the generator to the power system check?
Phase sequence 
If an operational check of the shaft runout is required, make it after the generator?
Is operating under full load
In planning a major overhaul of a hydroelectric unit, one of the best sources of information is?
Maintenance records
Determining the condition of the equipment should be done by performing a thorough inspection of the unit?
6-12 months before planned overhaul
A list of _____ for all of the machines components should be made from the drawing information.
Weights
If substantial welding is needed, the a __________ for the required repairs should be written and distributed to all the personnel that will be involved in the welding.
Welding procedure
Units with replaceable seal rings should have a ______ onsite.
Spare set
Shaft runout readings, bearing temperatures, pressures and permanent magnet generator (PMG) voltages are all part oF?
Pre shutdown readings
Preteardown readings include?
Shaft alignment readings, guide bearing clearance, seal ring clearance, and generator air Gap
To make sure parts are installed in exactly the same position from which they are removed, they should be ________ prior to removal
Match marked
The rigging to lift the thrust block should include a ______ so that the block can be kept level to prevent binding when it is lifted off the shaft.
Turnbuckles
After removing thrust and guide bearings, minor scratches and even some deep gouges can be adequately repaired by ____ the high spots from the babbitt surface.
Scraping
In most cases the repair of ___ damage can be accomplished much more effectively with the runner removed from the turbine pit as the runner can be positioned for easier access.
Cavitation
Where an overlay of a dissimilar materials is being used such as stainless steel over mild steel ,enough material should be removed to allow at least ___ weld passes to be made.
Three
The interior bore of the packing box can be built up with ___ ___ as long as the box is structurally sound.
Epoxy coating
Bearing cooling coils should be thoroughly inspected and _______tested.
Hydrostatically
To fin the units center, the upper bridge and headcover should be installed after all the _______ parts have been removed. A _____ wire should be hung through the unit and reference measurements taken from the stator, the turbine bearing housing, the packing box bore, and to trammel points in the draft tube
Rotating; single
Dowels have a very ___ fit to prevent the components from shifting once the part is positioned.
Tight
When doweled components are moved during the alignment process following the overhaul of a unit _______, is necessary
Redoweling
A more accurate method of measuring the preload of a coupling bolt is to measure the amount the bolt ___ as the nut is tightened.
Stretches
When aligning a unit, it is important to make the bearing centers all ____, the shaft must be perfectly plumb. This can be accomplished by installing the turbine bearing and shimming the shaft to center in the _____ bearing(s)
Concentric; Turbine
When setting clearances on upper and lower guide segment show bearings, install a feeler gauge to check clearance by?
Inserting the feeler gauge so that it extends all the way through the bearing
When working on wicket gate adjustment the amount the servomotor travels after the gates contact each other is referred to as the?
Squeeze
There should be ___ leakage upon the initial startup after the installation of new turbine shaft packing. The packing gland should be ___ evenly and in small steps until the leakage is reduced sufficiently.
Generous; tightened
A very thorough inspection of the ___ ____ and the ___ ____ should be made to check for any bolts, nuts, tools, etc.
Generator housing; spiral case
to prevent the damage tat could occur from circulating currents passing through them the following are insulated from the frame and should be checked with an ohmmeter prior to startup.
Upper guide bearing, Thrust bearing, PMG
Operational readings should be taken once the unit has been determined to operate with no problems, they include?
Bearing heat run, Shaft runout readings, Load rejection tests
