3rd 6th Month Final Flashcards
1
Q
Not wearing required protective equipment
A
Unsafe acts
2
Q
Four main types of hazards
A
Electrical, chemical, mechanical, and environmental
3
Q
An example of Contacted-by accident
A
A splash from a chemical
4
Q
If you discover a spill, do not attempt to clean it up unless
A
You have been specifically trained to do the job
5
Q
What should you do first if you think you are in a dangerous situation that takes action right away
A
Ask your supervisor to eliminate the danger
6
Q
What should you do if you see a way to make your job safer
A
Tell your supervisor about it
7
Q
The hazard communication standard has five main objectives
A
Reduce workplace injuries and illnesses, require chemical manufacturers and distributors to identify chemical hazards, communicate chemical hazards to all employees, and to replace state right-to-know programs with a uniform federal standard, and
8
Q
OSHA requires all employees to be
A
Trained to recognize and handle safely all chemicals at work
9
Q
What section of the MSDS identifies the personal protective equipment required for your physical safety and also includes personal hygiene methods and ventilation recommendations
A
Control Measures
10
Q
OSHAs main concern is
A
Employee safety
11
Q
EPAs main concern is
A
Environmental protection
12
Q
One responsibility of your employer regarding personal protective equipment is
A
Conduct a survey to identify the PPE to be worn in the workplace
13
Q
Why do glove manufacturers publish the results of their testing in a chart
A
So the right gloves can be selected more easily
14
Q
How much clearance should a hard hat provide
A
1” clearance between your head and the top of the shell
15
Q
What offers better protection than safety glasses
A
Safety Goggles
16
Q
Two kinds of atmosphere-supplying respirators
A
Supplied-air respirator and self-contained breathing apparatus
17
Q
What are chemicals that cause explosions, fires, or violent chemical reactions
A
Physical Hazards
18
Q
Chemicals that can cause illness or injury when inhaled, swallowed, or touched
A
Health Hazards
19
Q
Health Hazard categories
A
Irritants Corrosives Sensitizers Target-organ chemicals* Reproductive hazards Carcinogens
20
Q
From the stomach, chemicals go into the ________ where they are absorbed into the bloodstream and travel throughout the body
A
Intestines
21
Q
What helps control chemical hazards
A
PPE (personal protective equipment )
22
Q
What should you do for inhalation first aid
A
Assist the victim to an area of fresh air, outdoors of necessary. Get medical help
23
Q
Wrench safety tip
A
Fully engage the wrench’s jaws with the nut
24
Q
Gloves, ties, and loose clothing or hair is not appropriate around
A
Revolving tools like grinders, drills, and saws
25
What does the grounding (third) wire protect you from
Shock and burns
26
What should you do before you disconnect a pneumatic hose or tool
Turn off air supply and release the pressure
27
Gasoline engines should only be refueled after
Engine has cooled
28
80% of the workers who are injured while handling materials hurt the
Lower part of their backs
29
Important rule for lifting
Keep your back straight
30
Who is allowed to operate forklifts or special-purpose trucks
Only trained and authorized operators
31
Accidents can be prevented on conveyors if
Workers are careful to turn off power and lock it out while work is being done
32
When is it safe to stand under a suspended load
Never
33
Guards that do not move when the machine is in operation are
Fixed guards
34
If the guard is 32" or more from the danger point, the opening can be as large as
6"
35
What type of guard had no physical barrier between the operator and the danger zone
Presence-sensing guard
36
What must you do to bring a machine to a zero energy state
Push the start button to make sure the power is off. Then push the stop button to prevent accidental start-up once power is turned on again
37
When should tags be bypassed or ignored
Never
38
The loss in potential, per unit charge, is called? And is measured in?
Voltage drop or potential difference between two places.
Volts
39
How is Ohm's law written
V = IR
40
A hot wire is either
| _________ or __________
Black or Red
41
What will happen if u touch someone who is in contact with the electrical source
You will become part of the circuit too
42
What is the most common way of preventing the accumulation of static electricity.
Grounding
43
Unplanned connections to ground are called
Ground faults or unintentional grounding
44
Fuses and circuit breakers are designed to act as
| __________ for electrical circuits
Safety Valves
45
An example of a typical hazardous electrical location is
Petrochemical Plants
46
If something is designed to release only low levels of electrical energy it is referred to as
Intrinsically safe
47
It is important to keep electrical enclosure doors secured and locked. And _______________ when equipment is energized
Door screws be tightened
48
The fire triangle does not take in to account what fourth element
Chain Reaction
49
The combination of the the four fire elements make up the
Fire pyramid
50
What class are fires of flammable or combustible liquids, gases, grease, and similar materials
Class B
51
What is the symbol for class B flammables
Red Square
52
What puts out a fire by reducing the temperature of the fuel
Water
53
What should you do with a fire extinguisher after use
Turn in for refilling
54
What should you use to lift instead of your back
Legs and arms
55
Alpha, beta, and gamma rays are examples of
Ionizing radiation
56
Workers can be exposed to __________ when performing brake or clutch repairs
Asbestos particles
57
Who has issued many rules and regulations governing the control of chemicals and waste
EPA (Environmental Protection Agency)
58
Any platform or work surface above ______ feet requires fixed railing
Four
59
How far out a ladder should be placed from the wall is called the
4 to 1 rule. Ladder should be 1/4 the working length from the wall
60
What occurs when the body cannot cool itself sufficiently
Heatstroke
61
What is one of the most important safety concerns for workers in confined space
Atmosphere
62
_______ is a very sensitive organ and is particularly vulnerable to the intense light, radiation, heat, and sparks from welding
The eye
63
Pneumatic equipment may be different, but they all convert __________ in to work
Compressed air
64
An example of a positive-displacement compressor
Reciprocating piston
65
A piston moving back towed the crank created enough pressure to permit air at __________ to open the valve and push air into the expanding space
Atmospheric pressure
66
_________ power is needed to compress the air because cooling between stages reduces the volume of air that is compressed in the second stage
Less
67
the two primary functions of compressor lubricating oil are to reduce friction and to
Improve the transfer of heat in the compressor
68
Relieving the internal pressure so a compressor is easier to start is called
Unloading
69
Single stage vane compressors are capable of developing up to ______ psi discharge pressure
50psi
70
Screw compressors operate at speeds between ________ and ________ rpm
3,000 and 12,000 rpm
71
An example of a low-pressure high-volume compressor is a
Impeller compressor
72
Two disadvantages of centrifugal compressors are
They require more horsepower per CFM than other compressors and they operate at very high speeds
73
The most efficient method of controlling centrifugal compressor output is
Speed variation
74
Unless really dry air is required, most plants simply _______ the _______ with an after cooler and remove condensed vapor
Cool the air
75
_________ ___________ is economical for large compressors or any that operate more than 10 hours a day
Water Cooling
76
What is caused by the physical attraction that an unsaturated desiccant and moisture have for each other
Adsorption
77
When the air receiver is the correct size for the volume of air in the system it allows the receiver to balance off available compressor capacity against
Much larger peak air-flow demands that occur
78
How does a non-centrifugal inertial separator work
Instead of following a circular path, the airflow is made to change direction sharply several times as it passes through the filter
79
Very fine oil particles in compressed air are called
Aerosols
80
If a filter stops 100% of a given particle size, the size is referred to as its
Absolute rating
81
Wetted filters have a higher initial cost than dry filters because they can be
Cleaned many times
82
With this type of lubrication, more positive lubrication is available at greater distances from the lubricator and is especially effective with complicated piping systems and intermittent equipment operation
Fine lubricators
83
What occurs when air-flow velocity is increased or air is forced to flow through a smaller line
Turbulence
84
_________ pressure is affected more by friction with the walls of the piping than is airflow at ___________
pressure
Lower
| Higher
85
All horizontal Compressor discharge and distribution lines should slope approximately __________
The slope should be __________ in the direction of the airflow
1" for every 10' of pipe
| Downward
86
NPT has a spiral clearance along the crest of the thread, and it seals against air leaks with flank-to-flank (side to side) contact, with the aid of
Pipe compound (pipe dope)
87
When disconnecting air lines, a blast of escaping air can blow _______ or ________ into your eyes or face
Dirt or chips
88
A valve with four primary connections and either four or five external ports
Four-way valve
89
A special four-way valve with five external conditions, all connected to primary system connections
Five-way valve
90
An excellent valve for very high-pressure service or as a throttling or flow-reducing device
Needle valve
91
The most widely used valve that is easy to operate, even with high pressures, because the internal forces balance each other
Spool valve
92
Valves that are used to simplify pneumatic circuits
Four-way valves
93
Many four-way valves have two _________ ports, but are still classified as four-way valves
Exhaust
94
The pressure at which the valve initially opens, determined by the adjustment of the spring
Cracking pressure
95
Diaphragm relief valves open much faster than poppet valves because
The compressed air works on a larger pressure-sensitive area than in a poppet valve
96
A valve that it's only job is to protect the system and its components from damage in the event that the pressure control should fail
Pressure-relief valve
97
How does a pressure regulator work
As air passes through the regulator outlet, a small amount is bled off into the underside of the diaphragm, forcing the diaphragm upward against the spring pressure. When the secondary pressure equals the spring pressure, the sealing element is pulled upward, closing off the valve opening. As the secondary air is used, the line pressure drops, allowing the diaphragm to move down, which permits more air to flow through the valve
98
A valve that restricts the amount of exhaust air that can pass from the cylinder through the valve and governs the speed at which the cylinder can retract
Exhaust-flow control metering valve
99
Pivoted cylinder mountings are classed as being
Trunnion or clevis
100
Checking a control valve to determine if it is capable of handling the air of a cylinder is commonly referred to as
Calculating the capacity coefficient
101
Piston motors have a stalling torque almost __________ the starting torque. It takes less torque to keep a motor turning than to start it. And even more torque to stall it
Double
102
The horsepower output of pneumatic motors is the product of
Shaft speed and torque
103
On a typical horsepower curve, the maximum power output is obtained at ________ speed and _________ torque output
Medium
| Medium
104
The thrust of the piston against the _________ ________ attached to the offset shaft causes the cam plate to rotate
Wobble Plate (or cam)
105
The force of a hydraulic fluid is spread over a __________ area, so it creates a ________ pressure
Smaller
| Greater
106
What takes in a volume of air from the atmosphere and compress it to a smaller volume to increase its pressure
Compressor
107
What are centrifugal and axial-flow rotary compressors classified as
Dynamic or nonpositive-displacement
108
What generally determines the size of a filter
Intake requirements
109
Why is corrosion resistant piping used
Because water tends to promote rust and scale in pipes and fittings
110
After lubricating oil is added, the air should travel no more than
30 feet
111
What are used for showing the physical relationship and interconnections between components
Pictorial symbols or views
112
What symbols clearly emphasize the function and method of operation of components
Schematic Symbols
113
Pilot and signal lines are drawn as a
Series of long dashes
114
Understanding a circuit can be best accomplished by studying
Small segments at a time
115
What happens when it is almost impossible to draw it as a composite schematic symbol, or even as a cutaway view
Manufacturer then devises a graphic symbol
116
According to ASME codes, receivers must be equipped with
Pressure gauges and safety valves
117
Slightly oversized pipe sizes are especially desirable when
The pipes are long and the system must meet the demands of a considerable number of tools or other types of pneumatic equipment
118
Pipe supports should be placed close enough together to prevent
Any appreciable sag
119
If a tubing flare is not a good one, what should be done
Cut it off and do it over
120
As a general rule, how long can pneumatic hoses be
Should not be any longer than necessary
121
What is the purpose of a planned maintenance program
To ensure that all equipment is checked on a regular basis
122
What can excessive line pressure result in
Accelerated wear
123
Air control valves for industrial control circuits are, for the most part, designed and built for use with pressures up to
150 psi
124
When is it best to do a daily maintenance report or checklist
Beginning of shift
125
Where can you usually obtain records of control-valve and cylinder operating cycles
Production records
126
Troubleshooting checks themselves are determined by
Type and number of components and by the operation that the machine performs
127
In many plants, the sequence of troubleshooting starts at the ________ ________ and proceeds through the system to the actuator
Air supply
128
The system description and operation section provides a concise description of
Signal, logic, and actuation functions
129
What happens when piston seals become worn and leak
Air continually leaks through the exhaust ports
130
If the valve action is sluggish, check the ________ _________ for insufficient lubrication or swollen seals
Moving parts
131
Heat generated during compression is controlled in what two ways
Cooling and limiting the pressure of the compressed air
132
If the surrounding air is dusty or oily, more frequent cleaning, possibly with a ___________ or __________, is required
Detergent or steam
133
The shorter life of discharge valves is a result of heat and accumulation of ____________
__________
Carbon deposits
134
One way to check if the trouble is in the starting unloader system, is to let out all of the air in the ___________
____________ and start the compressor again
Compressor reservoir
135
3 maintenance items that are the same for all rotary compressors
Lubrication, bearings, and seals
136
A control malfunction can be isolated by analyzing the performance, or lack of performance, of the
Components in the pneumatic circuit
137
In some circuits a loss of power may put the circuit _________ ___ ___________ or stop it entirely
Out of sequence
138
Solenoids are activated by a magnetic field set up by the flow of __________ _____________ in the coil.
Electrical current
139
Air demands from other machines connected to the common air supply may periodically __________ _____ ________ ________ ____ ____ _________
Where the circuit is troublesome
Reduce the air pressure to a point
140
Valve shifting without a signal is caused by one of two factors
Vibration or momentary loss of pressure
141
Heavy oils are not recommended because they can gum up or form _________ on the moving parts of the valve and in its bore
Varnish
142
If the controls stick, check to see if the seals are
Swollen or soft
143
What kind of cylinders are used in most industrial applications
Tie-rid cylinders
144
Most industrial pneumatic cylinders are supplied with a bushing or gland in the front head. This gland acts as a support, or ___________, for the piston rod as it travels back and forth during its work cycle
Bearing
145
Most pneumatic cylinder seals have a maximum heat resistance of 180*F to ________*F. Applications that involve higher temperatures or other harmful conditions require special seals
200*F
146
Improperly torquing tie-rods causes
Internal misalignment
147
The only function of the cushion sleeve is to protect
The cylinder from damage
148
Without clean, filtered air, air motors will have a
Limited service life
149
When installing couplings, lubricate the nipple and inside the hose with a _________ _________ if the fitting is difficult. Never use oil or grease on a coupling
Soapy solution
150
When you repair air motors or tools, remember that they are
Precision built
151
Inspect the ________ or __________ ___________ of a pneumatic grinder
Arbor or motor shaft
152
Because of their _________ ____________ ___________, radial-piston air motors require less maintenance than other air motors
Slower operating speeds
153
In air-oil tanks, because the hydraulic oil is pressurized by compressed air, the pressure achieved in the system is substantially lower than that of a conventional hydraulic system. To overcome this lower pressure, relatively large _________ ___________ are required for anything except low output force.
Work cylinders
154
The main components in a booster are its
Air piston and hydraulic ram
155
The __________ ____________
| Valve is used to adjust the oil levels between the makeup tank and return tank
Manual shutoff
156
The possibility of air leakage in an air-oil cylinder is eliminated by placing a ________ _________ or _________ between the two sets of rod seals in the center of the unit
Bleeder space or passage
157
The two independent actions of a air-hydraulic system are used for economy and ________
Speed
158
In an automatic interlocked air-oil system, the two actuating valves reduce the response time required for the valve shift, which increases
The speed of operation
159
Pipe up to 12" diameter usually is designated by its
Nominal inside diameter
160
Pipe is generally coated on the outside with galvanizing, paint, insulation, or some other substance to prevent
Corrosion, condensation, and heat loss
161
The thread used on pipe is the
Tapered "V" shape AS or NPT
162
For low pressures and cold services, _________ gaskets are generally used
Rubber
163
To differentiate between pipes carrying different substances, pipe systems are often
Color coded
164
All pipe systems should be installed in accordance with the
American Standard Code of Pressure Piping
165
Piping should be supported to provide the necessary rigidity to
prevent Metal fatigue, prevent sagging, and to provide drainage
166
__________ strainers are commonly used where frequent cleaning is necessary
Duplex
167
__________ ___________ strainers are used to automatically strain raw water to remove silt and debris
Self-cleaning
168
Warm-up or __________ ____________ lines reduce wear and make large valves easier to open
Pressure equalizing
169
A ____________ line is used to control the concentration of impurities in a pressure vessel
Blowdown
170
The most versatile of the many kinds of plastic pipes is __________. It is inert in continuous service to all acids, caustics, chlorides, solvents, and bleaching agents
Teflon
171
An unexpected event that results in injury to an employee, illness, or damage to property
Accident
172
Force per area unit
Pressure
173
The input component of a system
Pump
174
The output component of a system
Actuator
175
The power source of a system
Prime mover
176
How to abbreviate Mercury
Hg
177
What is caused by a resistance to flow
Pressure
178
The pressure at the pump is the _________ of the pressure required to open individual valves
Sum
179
________ depends on cylinder size and rate of oil flow to it
Speed
180
Friction varies as the square of the
Velocity
181
_______ does not take in to consideration how fast the job gets done
Work
182
HP = GPM x psi x ________
0.000583
183
The first step in designing a simple hydraulic system should be the selection of an
Actuator
184
Where should a relief valve be installed?
Between the pump outlet and the inlet port of the DCV
185
A hydrodynamic device is
A hydraulic device that uses the impact or kinetic energy in the liquid to transmit power
186
A hydrostatic device is
When the device is operated by a force applied to a confined liquid
187
The tendency to cause flow may be supplied by a mechanical pump or may be caused simply by the ________ of the fluid.
Weight
188
What comes from the weight of the fluid?
Pressure Head
189
At sea level, a column of air one square inch in cross section and the full height of the atmosphere weighs?
14.7 lbs
190
A perfect vacuum is the complete absence of pressure or _______ psia
Zero
191
A measure of the volume of fluid passing a point in a given time is?
Flow rate
192
inches cubed / minute =
GPM X 231
193
When a fluid _______ through a constant-diameter pipe, the pressure will always be slightly lower downstream with the reference to and point upstream
Flows
194
When the particles of a fluid move though a pipe, they will move in straight, parallel flow paths. This is called
Laminar flow
195
What is caused by abrupt changes in direction, cross section, or by too high of velocity
Turbulent flow
196
Hydraulic fluid Ina working system contains energy in two forms: _________ energy by virtue of the fluids weight and velocity, and _________ energy in the form of pressure
Kinetic
| Potential
197
A ________, or sensing line carries fluid that is used to control the operation of a valve or other component
Pilot
198
The triangle pointing ______ shows the motor receiving energy
In
199
Infinite positioning pressure and flow control valves have ________ envelopes.
Single
200
Three boxes in a DCV means the valve has three _______
Positions
201
Connecting lines are drawn to the ________ of the reservoir symbol when the lines terminate ________ the fluid level in the tank
Bottom
| Below
202
What are the purposes of hydraulic fluid?
Provide cooling of the system and its components via dissipation of heat through the reservoir and/or cooling devices, lubricate sliding or rotating surfaces in components, seal the running clearances in components to minimize internal leakage, and carry away contaminants in the system to the filters or to the reservoir where they are allowed to settle out of the fluid.
203
Fluids used in hydraulic applications are also required to be compatible with component materials such as _______ and hose interior linings.
Seals
204
The physical size of clearances, pressure drop across the clearances, and the operating _________ of the fluid determine the leakage rate.
Viscosity
205
The viscosity of a fluid may be defined as its resistance to _________ at a given temperature.
Flow
206
___________ is defined as resistance encountered when moving one layer of liquid over another
Absolute viscosity
207
___________ is the most common way of measuring viscosity
Kinematic viscosity
208
___________ is a dimensionless number that characterizes the variation of viscosity of a fluid with variations of temperature
Viscosity index
209
Lowest temperature at which a fluid will flow
Pour point
210
There may be numerous oxidation __________ present in poorly maintained hydraulic systems
Catalysts
211
7 things that accelerate oxidation
```
Heat
Pressure
Contaminants
Water
Metal surfaces
Some metals
Agitation
```
212
_________ is a chemical reaction between a metal and a chemical
Corrosion
213
__________ is the ability of a fluid to separate out or reject water
Demulsibility
214
Synthetic and water-based fluids are typically heavier than petroleum fluids and may require flossed inlet conditions to prevent __________ of pumps.
Cavitation
215
_________-in-oil (invert) emulsions
Water
216
Pipe and pipe fittings are classified by _________ size and wall thickness
Nominal
217
Schedule _________
| Corresponds closely to standard
40
218
Tubing is designated by the
Outside diameter
219
Tubing end connectors can be a flared type, compression _________ type, and brazed or welded type
Fitting
220
The ______ _______ is installed in an annular groove machined into one of the mating parts
O-ring
221
Lip seals are low pressure dynamic seals, used principally to seal _________ __________
Rotating shafts
222
Synthetic runners are known as
Elastomers
223
The elastomer __________ (Buna-N) is a widely used sealing material in modern hydraulic systems. It is moderately tough, and is ______________
Nitrile
| Inexpensive
224
Nitrile retains its sealing properties from ___________
- 40* to 250* F
| - 40* to 121* C
225
_________-mounting of valves with all connections made ___________ to a mounting plate has made a great difference in preventing leakage.
Back
| Permanently
226
At too high of temperature, a seal may harden, _________, or swell
Soften
227
The filler opening has a ___________ __________ that keeps contaminants out of the tank
Removable screen
228
Fluid returning to the reservoir is usually __________ than the supply fluid
Warmer
229
__________ are used to prevent the warmer returning fluid from directly entering the pump inlet
Baffles
230
Connections made on the top of the reservoir are often set on _________ to keep then above dirt
Risers
231
Lines that terminate near the tank bottom and are not equipped w strainers should be cut at a _________ degree angle
45
232
Name 3 types of standard reservoirs used today
Flat top
L-shaped
Overhead stack
233
Size the reservoir for at least ______ percent overcapacity
20
234
Tank size (gallons) =
GPM x 2 or x 3
235
Fluids with a ______ viscosity index will not flow readily when cold
Low
236
Name three types of heat exchangers
Heaters, air coolers, water coolers
237
Three sources of hydraulic system contamination
Built in
Ingressed
Internally generated
238
The naked eye can see down to
40 micrometers
239
1 micron =
.000039 in
240
Another frequent ________ failure is a contamination blockage which prevents the solenoid spool from shifting
Transient
241
Components are affected in different ways by contamination, depending on their _________
Design
242
If the fluid is contaminated, rapid degradation and possibly _________ will occur
Seizure
243
The preferred location for sampling is directly _________ of the return love filter element
Upstream
244
Tubing must not be welded, _______, or soldered
Brazed
245
To transfer oil from drum to the hydraulic reservoir, an oil pump equipped with a ________ micron filter is recommended
5
246
Compared to a filter, an inlet strainer is relatively __________
Coarse
247
_________ __________ filters can trap much smaller particles than inlet line strainers
Pressure line
248
What term applied to a filter means all the flow generated by the system passes through the filtering element
Full flow
249
A coarse filter with pores larger than 50 microns
Strainer
250
The higher the mesh or sieve number means
The finer the screen
251
Correct filter sizing requires
Flow capacity
Type of dirt entering filter
Pressure drop
252
To minimize _________ _________, the average pressure drop across the filter should be as low as possible
Energy consumption
253
To test for material compatibility, the element is immersed for _____ hours in system fluid that is 59*F higher than rated max temp
72
254
Two basic classifications of filtering materials
Absorbent
| Adsorbent
255
__________ tubes are used to support the media against pressure differential
Perforated
256
Elements employing ________ media are used as strainers for coarse filtration
Surface
257
Hydraulic filter elements for fine filtration requirements are most frequently made of a glass fiber material and also tend to have a _______ structure
Pleated
258
A _________ valve is incorporated into the housing to eliminate the possibility of element collapse
Bypass
259
All filters include a filter condition ________ so the user will know when the filter element should be replaced
Indicator
260
________ points must be provided to monitor initial and subsequent levels of contamination
Sampling
261
A ram type actuator is mounted vertically and retract by the force of _______ on the load
Gravity
262
In a _________ _________ _________, pressure is applied to either port, providing powered motion when extending or retracting
double acting cylinder
263
Displacement is the amount of fluid required to turn the motor output shaft one ________
Revolution
264
Displacement is measured in cubic inches per
Revolution
265
The size and torque rating of a motor usually is expressed in pound inches of torque per _______ psi of pressure
100
266
Hydraulic motors can be classified into three categories
High speed, low torque motors
Low speed, high torque motors
Limited rotation motors (torque actuators)
267
________ _________ motors will not permit continuos rotation in either direction
Limited rotation
268
Internal gear motors fall into two categories
Direct drive gerotor
Orbiting gerotor
269
The most efficient of the three types of hydraulic motors is
Piston
270
Pressure at the piston ends causes a reaction against a
Swash plate
271
In a basic hydraulic compensator control, as the pressure rises, the compensator spool will shift and allow fluid into the control piston. This will cause the yolk to rotate toward the max displacement, __________ torque and reducing output speed
Increasing
272
Directional valves control the ______ of fluid flow
Direction
273
A ________ valve is a one-way directional valve. It allows free flow in one direction, while blocking flow in the other direction
Check
274
A ________ way valve can be used to move an actuator in either direction
Four
275
The five categories of actuators are
```
Manual
Mechanical
Pneumatic
Hydraulic
Electrical
```
276
To control the shift speed of the main spool, a _________ _________ may be incorporated on a two stage valve
pilot choke
277
When it is necessary to increase main spool shifting speed, ________ _________ are used
Pilot Pistons
278
What restricts the distance the main spool can shift in a given direction
Spool stroke limiter
279
Line mounted sliding spool-type directional valves are more frequently found in _________ applications
Mobile
280
A typical application of a _________ valve is a machining operation that requires fast speed to move a part into place, and then a slower, controlled speed for the actual machining operation
Deceleration
281
One drawback of the _________ _________ is that at low flow rates, this control is only available from the point where a pressure drop is created
Tapered plunger
282
A deceleration valve also includes an adjustable _________ that permits the load to creep to its final position
Orifice
283
In a ________ valve, gravity or atmospheric pressure pushes the fluid through the valve
Prefill
284
___________ valves decompress fluid before the valve is shifted to return to the cylinder to help avoid possible damage from hydraulic shock
Decompressing
285
A relief valve is a normally _________ valve connected between the pressure line and the reservoir
Closed
286
A relief valves purpose is to limit pressure in the system to a preset _________
Maximum
287
The pressure at which he valve first begins to divert flow is called the
Cracking pressure
288
The difference between cracking pressure and full flow pressure is sometimes called pressure
Override
289
Pilot operated relief valves may be romotlely controlled by means of an oiler port from the chamber above the piston. When this chamber is _________ to tank, the only force holding the piston on its seat is that of a light spring
Vented
290
In a back pressure valve, it is necessary to maintain adequate back pressure to keep the valve ________
Open
291
To use a back pressure valve as an _________, the lower cover is assembled to block the internal operating pressure passages
unloading valve
292
In an unloading valve, the primary port pressure is independent of the spring force because the _________ pressure operates the spool
Remote
293
In an unloading valve, as long as the control pressure is at least ________ psi above the spring setting, free flow is perimeter form the primary to the secondary port
150
294
A _________ valve is used to cause actions to take place in a system in a definite order
Sequence
295
In a sequence valve, if pressure was was allowed in the drain passage, it would add to the spring force and ______ the pressure required to open the valve
Raise
296
A sequence valve is suitable for systems where it can be installed upstream from the directional valve. If it is installed _______ _______, some provisions must be made for return free flow when the cylinder is reversed
Downstream
297
In a counterbalance valve, the pressure setting is slightly _______ than is required to hold the load from falling
Higher
298
A brake valve is used in the _______ line of a hydraulic motor
Exhaust
299
When the load is being _________, pressure is maximum at the motor inlet
Accelerated
300
A typical method used to control the speed of hydraulic cylinders and motors is the use of a _________ _________ _________
Flow control valve
301
In a _______ ________ operation, the flow control valve is placed between the pump and the actuator
Meter-in
302
Metering into the cylinder works well with an opposing load, but if the load tends to run away, a more positive approach is to utilize a _______ _______ circuit
Meter-out
303
A ________ ________ circuit is installed in a branch circuit off the main line to control cylinder speed
Bleed-off
304
At 20 psi a bypass valve piston is usually _______
Closed
305
At 20 psi a restrictive type pressure compensated flow control valve piston is usually _______
Open
306
In a temperature compensation valve, the center rod in the throttle spool ________ when heated
Expands
307
The use of any type of proportional valve requires that the equipment contain an _______ ________ supply and electronic controls
Electrical power
308
Deceleration valves are restrictive type flow controls and they are usually used in the _______ _______ configuration
Meter-out
309
Flow capacity of a pump can be expressed as displacement per revolution, or as __________ _____ _________
Output in GPM
310
__________ is expressed in cubic inches per revolutions
Displacement
311
Volumetric efficiency is equal to the actual output divided by the ________ output
Theoretical
312
___________ displacement pumps have a displacement that cannot be changed without changing some internal components of the pump
Fixed
313
Gear pumps are referred to as an ________ design
Unbalanced
314
The displacement of most _________ design vane pumps cannot be adjusted
Balanced
315
Holes drilled through the rotor segments ________ pressure above and below each vane at all times
Equalize
316
In _________ _________ pumps, the Pistons reciprocate parallel to the axis of rotation of the cylinder block
Axial piston
317
__________ provide a way to store fluids under pressure
Accumulators
318
The energy storage capability makes accumulators capable of acting as ________ _________
Shock absorbers
319
In a weight loaded accumulator, the pressure is always _________
Constant
320
The most popular type of accumulator has a chamber that is pre charged w a compressible gas, usually _________. __________ is most commonly used because it is a stable gas that will not react with most fluids used in accumulators.
Nitrogen
321
In a gas charged accumulator, the precharge should never be less than _____ and preferably 1/3, of the maximum working pressure
1/4
322
A _________ is a device used to multiply pressure
Intensifier
323
___________ switches open and close electrical circuits at selected pressures
Pressure
324
Two principal types of pressure gauges are the _________ __________ and the __________ type
Bourdon Tube
| Schrader
325
Vacuum gauges are calibrated in inches of ________ and psig
Mercury
326
The __________ prevents the gauge from oscillating and protects it from pressure surges
Snubber
327
A fluid is any substance that __________
Flows
328
The purpose of the steam trap is to bleed the hot _________ out of the system so that only steam is carried through the system
Water
329
__________ __________ are the parts that connect sections of pipe
Pipe fittings
330
___________ and corrosion reduce the inside diameter of the pipe which causes a pressure drop
Sludge
331
The amount of friction increase as the ___________ of the velocity
Square
332
Above 12", a pipe is usual designated by its _________ diameter
Outside
333
Utility or __________ lines carry steam, gas, water, compressed air, and air conditioning fluids
Service
334
A __________ metal is one that contains iron
Ferrous
335
As __________ rises, so does friction in the pipe
Viscosity
336
__________ _________ happens when a moving column of water is suddenly slowed or stopped
Water hammer
337
___________ __________ pipe is the most corrosion-proof product available for industrial and sewage waste
Vitrified clay
338
Joining two lengths of asbestos-cement pipe is accomplished by using an asbestos-cement __________. The ___________ acts as an expansion joint.
Sleeve
| Gasket
339
A key reason for using ___________ pipe is for its self-insulating properties
Plastic
340
__________ weakens the wall strength of the pipe
Threading
341
Glass pipe has a great resistance to corrosion, __________, and heat.
Contamination
342
Because of its relatively small diameter and __________, tubing can be used in tight places where pipes would be very difficult to install
Flexibility
343
Because they are flexible, tubes can be run from one point to another with fewer __________ than if pipe were used
Fittings
344
When you cut ________ _________ tubing with a tube cutter, it becomes more "work hardened"
Stainless Steel
345
Joints are made by ________, and by gas or arc _________
Brazing
| Welding
346
The methods of joining __________ tubing include two kinds of fusing, fusion welding, and cement-plus-binding
Plastic
347
To convert to dash system is you must
Convert to 16th ( 1-1/4 = 20/16 = -20)
348
Hose usually has layers of high strength synthetic cord _________ called braid
Reinforcement
349
The degree of vacuum that can be created before a hose begins to collapse
Vacuum rating
350
__________ is used in applications where hoses are required to carry corrosive fluids and fluids at temperatures of up to 232*C
Teflon
351
If the hose failure is at one end, cut off at least _____ ________ of the hose beyond the damaged area before decoupling. Then reverse the ends of the hose
1 Foot
352
The term 250lbs refers to the ________ at which the fitting can safely be used
Pressure
353
In the long-radius elbow, the center-to-face distance is always _______ times the diameter of the fitting
1-1/2
354
In the short-radius elbow, the center-to-center measurement equals the pipe _______
Diameter
355
The main flow passes through the straight _______ of the tee
Run
356
High temperature lines are usually made up with a large bend or loop to _________ ____ ________
Allow for expansion
357
________ _________also help reduce the effects of water hammer
Vibration Dampeners
358
A ________ valve would be selected for use in a pipeline with a 3" diameter
3"
359
The _________ is the main part of the valve that is connected to the piping
Body
360
Needle valves are used for very accurate _________
Throttling
361
A swing check valve offers __________ __________ _____ ________ when it is in the open position
Little resistance to flow
362
For industrial valves, the term ________ refers to what household plumbers call "washers"
Seals
363
The separation of the bonnet assembly from the fluid line means that lubricant or dirt from the bonnet assembly cannot get in to the fluid. This makes _________ valves excellent for use in applications where the fluid must be kept contaminate free
Diaphragm
364
Open the slow opening valve first under normal operating conditions. It ensures that the blowoff operation is started slowly and prevents _________ ____ _____ ________.
Shock to the system
365
Pressure regulating valves are necessary because all along the fluid lines the demands are __________ _________
Constantly changing
366
A safety valves refers to a valve used with _________ _____ ________. A relief valve is used with ________
Gases and steam
Liquid
367
A rupture-disk relief valves particular advantage is that it can
Relieve large volumes of gas or liquid quickly
368
Solid particles in a high pressure line can damage a valve in two ways
Clogging the valve so it can not close tightly
Wearing away the closely machined valve parts
369
A _________ filters has two identical filters side by side. One of them is always in use. When the filter element needs cleaning, the other side of the unit is switched into service
Duplex
370
The operation of a trap depends on ________ __________. Which is the difference between the inlet and outlet pressure
Differential pressure
371
Trap maintenance includes periodic cleaning and removing _______ that interferes with valve action
Sludge
372
The total or actual pressure is called the _________ pressure. Gauge pressure plus atmospheric pressure
Absolute
373
In a Mercury thermometer the bulb and capillary are contained inside a protective _______ ________ called a well
Metal tube
374
The purpose of a vacuum breaker is to _______ _______ into the line whenever a vacuum developes
Admit air
375
When adjusted to a desired pressure, the ______ automatically maintains that pressure
Regulator
376
In a compressed air system, the air coming from the _______ is hot. In order to cool it down, compressed air systems often include a water-cooled ________
Compressor
After cooler
377
Hydraulic systems covert the available power to ________ power at the location where it is required
Usable
378
Name three basic types of control valves
Directional
Flow
Pressure
379
Fluid acts as a carrier of hydraulic power through the system, but it also serves the important function of _________ the hydraulic equipment
Lunricating
380
When getting to know the system, the first thing to do is to _________ ____ __________ of the basic machine or piece of equipment on which the system is installed
Understand the operation
381
In order for the system to provide the correct hydraulic action, the valves and other components have to be ________ _________ and set up in the first place
Installed correctly
382
A ________ diagram shows the general location, purpose, and appearance of the systems elements
Pictorial
383
The basic purpose of a _________ diagram is to tell you exactly and completely what the system consists of
Schematic
384
The second basic characteristic of a schematic is that _______ are used to show elements of the system
Symbols
385
The two main steps of a methodical approach to reading a schematic diagram are
Get the overall view of the system
Study local areas of the diagram
386
Valve symbols show connections, flow paths, and ________ _________
Valve functions
387
Each major element in a hydraulic system has its own particular ________ that must be considered during installation
Features
388
Before the drive unit is installed, the hydraulic _______ should be installed and mounted rigidly
Pump
389
_______ the drive to make sure that the rotation direction is correct before running the system
Jog
390
Many people refer to _________ as sandwich plates
Manifolds
391
When removing a valve, never clip off the solenoid _________
Leads
392
The diameter of inlet piping should never be ________ than the intake of the pump
Smaller
393
The three principle considerations in selecting tubing are
Material
I.D.
Wall thickness
394
In tubing assembly, avoid _________ _________ connections that strain the tube or fittings, especially in short runs
Straight-line
395
Hose flexibility is its outstanding advantage, it is also the reason why it _________ _________ more rapidly than either pipe or tubing
Wears out
396
The primary function of a hydraulic function is to transmit efficiently the ________ and ________ applied at one point in the system to the point where the required mechanical action is produced
Force
Energy
397
The lubricating properties of a fluid are largely dependent upon its
Viscosity
398
_________ is the greatest variable affecting viscosity
Temperature
399
The hydraulic fluid must be _________ with the materials used in the system
Compatible
400
It is important to take precautionary steps to _________ the ________ of the system before installing new fluid
Ensure
Cleanliness
401
How often you inspect, what you inspect, and what you inspect for depend on the ________, it's environment, and its application
System
402
Inspection is a form of _________ __________
Preventive maintenance
403
A sample of hydraulic fluid should be taken at least twice a year, or every ________ hours, and sent out for laboratory analysis
1000
404
Never sacrifice _________ for production
Safety
405
Many companies find it best to completely recondition a system element when it has run for _________ years or more
Two
406
Troubleshooting is a term applied to a methodical system of cause - and - effect thinking. A series of __________ _________ is taken to find the cause of failure or malfunction of a system or its components
Logical steps
407
With all symptoms identified, the next step is to determine the _________
Cause
408
Gauges are equipped with divorces called _________, which keep the needle from fluttering and absorb sugars of pressure to protect the gauges
Snubbers
409
Flowmeters are used for ________ and monitoring purposes
Testing
410
The first step of troubleshooting is to take out the __________ folder for that machine and learn something about its operation
Maintenance
411
Before proceeding on the assumption that a valve has malfunctioned, you should _________ _____ ________
Test the system
412
When you disassemble a valve for repair or reconditioning, always __________ all the seals, even though they seem to be in good shape
Replace
413
Sludge formation is caused by the _________ of hydraulic fluid
Overheating
414
Could burn out from overheating when circuits cause __________ current flow
Excessive
415
Mechanical causes of solenoid malfunction are chips, hardened grease, or other solid _________ that hold the plunger open
Contaminants
416
Misalignment created by excessive ________ ________ causes the cylinder to bind and become inoperative
Side loading
417
If the __________ orifice is blocked or restricted, the fluid will not be allowed to pass freely through the valve, and the cylinder will not move or will move very slowly
Metering
418
The most popular types of fire-resistant hydraulic fluids are
Water based
Emulsion
Phosphate ester
419
Before connecting the cylinder, all pipe and fittings should be blown clean of _________, __________, and _________ ________
Dirt
Scale
Thread chips
420
Accurate ________ and _________ are essential to proper cylinder performance.
Mounting
Alignment
421
Because visual inspections while the pump is in operation are limited, _________ to the pump is the only other way of determining what is happening inside the unit
Listening
422
_________ _________ may cause other failures such as a fractured pressure ring, repeated shaft seal blowout, broken rotor segments, cracked and broken vanes and teeth, or a fracture in the pump housing.
Pressure shock
423
Excessive wear, scratches, or roughness means that solid ________ have been introduced to the pump
Contaminants.
424
__________ _________ pumps are designed for higher pressure applications and are manufactured with close tolerances
Axial piston
425
When any type of gear pump or motor is being repaired, it is good general practice to replace all
Anti friction bearings
Shaft seals
Gaskets
426
_________ permit the transfer of electric energy between two circuits which are completely insulated from each other
Transformers
427
The winding which receives the energy inductively from the primary winding is called the ________ winding
Secondary
428
A _________ condition must always exist between the primary and secondary fields to maintain the primary current to supply the transformer losses and secondary load
Balanced
429
When the number of turns or voltage on the secondary of a transformer is greater than that of the primary, it is known as a ________ ________ transformer
Step up
430
The power transformer transfers electric power from one circuit - at a certain frequency and voltage - to a second circuit at the same __________ and a different _________
Frequency
Voltage
431
Transformers are classed as static ________ machines
AC
432
Those used to step voltage down are known as ________ transformers and those used to step current down are known as _________ transformers
Potential
Current
433
The secondary terminals should never be _________ _________ because a heavy current will flow which will burn out the windings
Short-circuited
434
Transformers having only one winding are called _________ transformers
Auto
435
In a _________ _________ transformer, a section of both the primary and secondary windings are wound on each leg of the core
Core-type
436
Heat is developed in transformers because the hysteresis of the magnetic material or __________ of the molecules
Friction
437
__________ _________ occur in a transformer whenever the primary is energized even though no load is on the secondary windings
Iron losses
438
Exposure to the atmosphere lowers the dielectric strength of the oil in the conservator, but it in turn acts as a barrier to __________ the atmosphere from contacting the oil in the main tank
Prevent
439
The four types of bushings used on transformers as main lead entrances are
Solid porcelain bushings
Cable terminators or potheads
Oil filled bushings
Condenser bushings
440
Series street lighting systems require a source of constant _________
Current
441
When transformer or generator windings are connected wye, the voltage between any two lines will be 1.732 times the phase voltage and the line current will be the _________ as the phase current
same
442
When the primary is energized, the secondary of a potential transformer should never be _________ and the secondary of a current transformer should never be _________
shorted
Opened
443
The state of matter in which electrons are removed from atoms or molecules, creating an electrically conducting gas is a
Plasma arc
444
The arc, because it consists of the electrically conducting plasma, allows the current to flow briefly between the open contacts and thus prevents the magnetic field from __________ too quickly
Collapsing
445
The dryness requirements of the 510 psig system are more stringent than normal and maintaining adequate pressure in the breaker interrupter unit is _________
Critical
446
The air blast transfers the arc from the stationary fingers to the arcing probe almost _________
Immediate
447
A trip free operation occurs when the breaker is closed on a fault, or if the control switch is held in the trip position after a closing operation is ________. The mechanism is electrically trip free after the Y relay has dropped out
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