Final Flashcards
(390 cards)
1
Q
Pipes up to 12 inches diameter are usually designated by
A
It’s nominal inside diameter
2
Q
The most distinguished feature on a pipe thread is
A
It’s taper
3
Q
Rubber gaskets are generally used when
A
There are low pressures and cold services
4
Q
To differentiate between pipes carrying different substances pipe systems are
A
Often color-coded
5
Q
All pipe system should be installed in accordance with the
A
American standard code for pressure piping
6
Q
In general piping should be supported to provide the necessary rigidity to prevent
A
All three, metal fatigue, to prevent sagging to provide drainage
7
Q
Self cleaning strainers are used to
A
Automatically strain raw water to remove silt and debris
8
Q
Pressure, equalizing, lines reduce, where and
A
Make large valves easier to open,
9
Q
Plastic pipe is inert and continuous service to all
A
Acids, caustics, solvent. Most likely not used for oils.
10
Q
Some pipe may be coated to
A
Prevent external or internal, corrosion and erosion, to prevent heat loss
11
Q
A line used to control the concentration of impurities in a pressure vessel
A
A blow down line
12
Q
Which type of pipe would be affected the least by corrosion
A
Stainless steel
13
Q
(Work) equals in a cylinder
A
Force times piston, travel 
14
Q
Most compressors, such as the reciprocating compressor are
A
Of the positive displacement type
15
Q
The purpose of an intercooler on a two stage air compressor is
A
It reduces the power needed on a two-stage compressor
16
Q
The advantage of unloading a compressor is
A
It can run without delivering air
17
Q
Single stage vein compressors are capable of developing up to
A
50 psi
18
Q
Unlike piston or reciprocating compressors, this type of compressor operates at speeds between 3000 and 12,000 RPM
A
Screw or rotary
19
Q
The impeller compressor is designed for
A
High volume rather than high-pressure to deliver air
20
Q
If temperature increases as the pressure increases, what happens to the air
A
The ability of the compressed air to hold moisture also increases
21
Q
Water cooling in compressors is economical for
A
Medium size compressors for more than eight hours, a day and larger compressors operating more than 10 hours a day
22
Q
During peak flow periods, air stored in the lines and in the air receiver will
A
Keep the overall system pressure from dropping too low if it cannot another or larger receivers were required
23
Q
Inertial separators in a pneumatic circuit depend on the inertia of a heavy, moving particle to
A
Aid in the separation,the faster it is moving ,more rapid change in airflow
24
Q
In addition to dust in cloud, particles, compressed air has
A
Very fine oil particles in the .01 2.8 µm range also called aerosols
25
If a filter stops 100% of a given particle size this is called
Absolute rating
26
The pros of a fine lubricator are
The lubrication is carried greater distances from the lubricator and is effective with equipment that is intermittent
27
Laminar airflow in a pneumatic circuit is
When an airline can handle the volume of air, that it flows through with no obstructions
28
When installed as compressor discharge and distribution lines, all horizontal pipe should slope approximately
1 inch for every 10 foot of pipe downward
29
While , disconnecting airlines where eye protection because
A blast of escaping air can blow dirt or chips into your eyes or face
30
A needle valve is a two way valve and an excellent valve for
High-pressure service as a throttling or flavored reducing valve
31
Spool valves operate in high pressures, and
Controls air by sliding and is easy to move
32
Five way valves have five external connections, many four-way valves have
Two external exhaust ports
33
A diaphragm relief valve, responding to increasing air pressure opens much faster than a poppet valve
The diaphragm valve has a larger pressure sensitive area than a poppet
34
Pressure relief valves only job is
To protect the system, and its components from damage
35
Regulator valve closes when discharge pressure increases when the secondary pressure equals spring pressure
The ceiling element is pulled upward closing off the valve opening
36
The best way to guard against successive pressure in a regulator is
By relieving low volume excess pressure in the secondary pressure line, if large buildup occur, a separate relief valve must be provided
37
On double acting cylinders, because the rod takes up some of the surface area of the piston
Less pressure can be exerted on the rod side, then on the cap side of the piston
38
To limit the return, stroke speed of a cylinder is usually controlled by
An exhaust flow control metering valve
39
Pivoted cylinder mountings are crossed as being
Tonyan or Cuevas, mounting it is a cylinder that must be free to pivot
40
Checking the control valve to determine if it is capable of handling, the air of a cylinder is referred to as
Is referred to as calculating the capacity coefficient
41
Piston motors, have a stalling torque, almost double
The starting torque
42
It’s typical horsepower curve for a pneumatic motor shows that maximum power output is
Obtained at medium speed and medium torque output
43
On piston motors, the cam attached to the offset shaft causes
The camp plate to rotate ,this motion is transferred through gears to the output shaft
44
In an air boosters, an air pressure of 100 psi can create hydraulic pressure of
1000 psi if the air piston drives a small diameter hydraulic piston
45
Fluid is any substance that is like
A liquid or a gas that flows
46
A steam line is to direct The steam to the trap
which bleeds the hot water out of the system
47
Pipe fittings like elbows are the parts that connect
Sections of pipe, sections of hoses, and sections of tubing
48
Sludge and corrosion can reduce the inside diameter of pipe that results in
A reduction in pressure
49
It is a rule that if the speed of a fluid is double
The friction is increased four times what it was before
50
Above 12 inches a pipe is ordinarily designated
By its outside diameter
51
Utility or service lines Carry
Steam, gas, water, compressed, air, and air conditioning fluids
52
A metal that contains iron is called
Ferrous metal
53
As viscosity rises in pipes, so does what
Friction also rises in the pipe
54
Water hammer is when
Water in a pipe is suddenly stopped or slowed
55
The most corrosive proof available pipe for industrial and sewage waste is
Vitrified clay pipe
56
A similar pipe to concrete with reinforcing rods and rings, but in addition, a welded steel shell embedded in the concrete is
Cylinder concrete pipe
57
Plastic pipe rarely has to be insulated, because
It is self insulating
58
Is suite disadvantage of threading pipe is
The threading weekends, the wall strength of the pipe
59
The advantages of glass pipe include
It’s great resistance to corrosion, contamination, and heat
60
Most tubing is very flexible and has some give to them this allows tubing to
Tubing can withstand vibration
61
Tubing eliminates fittings
They are flexible and can be run from one point to another with fewer fittings then if Piper used
62
Stainless steel tubing should be cut rapidly because
When stainless steel tubing is cut, it can become work hardened
63
Aluminum tubing joints are made by
Brazing, and by gas or arc welding
64
Solvent, cementing and heating fusion welding are
The methods of joining plastic tubing by fusion
65
To determine the size of a hose simply convert the size into sixteenths a one and 1/4 can be pronounced as
– 20
66
A hose with two layers of high strength synthetic cord reinforcement is called
Braided hose
67
Vacuum rating on a hose refers to
The degree of vacuum that is created before a hose begins to collapse
68
Teflon is using applications where hoses are required to carry
Corrosive, fluids and fluids at temperatures of up to 450°F
69
When a hose is damaged, the proper repair is
Cut off at least 1 foot of the hose beyond the damage area before recouping, then reverse the ends of the hoses
70
The standard of fittings 250 pound refers to
The pressure at which the fitting can be safely used
71
In the long radius, elbow the center to face distance is
Always one and a half times the diameter of the fitting
72
In the short radius, elbow fitting the sensor to face measurement equals
The pipe diameter, C divided by F equals D
73
With fittings, high temperature lines are usually made up with
A large, bend or loop to allow for expansion
74
In piping systems Aside from the main purpose, vibration, dampers, also help reduce
The effects of water hammer
75
Valves are made in a full range of sizes which match pipe and tubing sizes for example, a 3 inch valve would be selected for use in a pipeline width
A 3 inch diameter
76
Needle valves are used for very accurate
Throttling
77
In the swing check valve the closing element swings open and shut like trap doors. What type of flow does this valve offer
Little resistance to flow
78
The seal in an industrial valve is the same part that is called
Washer in a household valve
79
The separation of the Bonet assembly from the fluid line in a diaphragm valve, makes it excellent for use and applications
Where the fluid must be contaminant free
80
The 5 360 turns of the hand wheel on a blow valve, insures that the operation it started slowly, and
Prevent shock to the system
81
Pressure regulating valves demand are
Constantly changing
82
Where are safety valves referred to valves with gases and steam? A relief valve is used with.
Liquids
83
The particular advantage to ruptured disc relief valves is that
It can relieve large volumes of gas or liquid quickly
84
Solid particles in a high-pressure line can damage a valve in two ways
It can clog the valve so that it cannot close tightly and it wears away at the closing machine valve parts
85
For duplex filters when one filter element needs cleaning
The other side of the duplex unit is switched into service
86
Differential pressure is the difference in
PSI between the inlet and outlet pressures
87
If the line carrying dry saturated steam, at a pressure of 100 psi and a temperature of 338 Fahrenheit or below and there’s a dropping pressure somewhere
The saturated steam will change into superheated steam
88
Trap maintenance includes
Periodic, cleaning, removing sludge that interferes with valve action 
89
Absolute pressure is
Gauge pressure +14.7 pounds of atmospheric pressure
90
The bulb of a mercury temperature gauge is in capillary tube are contained inside a protective
Metal tube
91
The function of a vacuum (siphon)breaker is
To admit air into the line , whenever a vacuum develops
92
When adjusted for desired pressure, the regulator automatically
Maintains that pressure
93
Water cooled after coolers purpose are
To cool the hot air coming from the compressor
94
A compressor takes a volume of air from the atmosphere and
And compresses it into a smaller volume to increase its pressure
95
The size of compressor filters is generally determined by
The machines intake requirements
96
Why should corrosion resistant piping be used?
Because water also tends to promote rust and scale buildup in pipes and fittings
97
After lubricating oil is added to the airline air should travel no more than
About 30 feet
98
Pictoral symbols on a diagram are very useful for showing
The physical relationship and interconnections between components
99
Schematic symbols on a diagram, more clearly emphasize
The function and method of operation of components 
100
Pilot or signal lines are drawn as
A series of long dashes
101
Understanding a pneumatic circuit can best be accomplished by
Studying small segments at a time
102
Symbols for special devices are drawn by
The manufacturer
103
Receivers must be equipped with pressure, gauges, and safety valves according to
A SME the American society of mechanical engineers
104
When installing pipe into a system, it is better to select a slightly oversized pipe because
It can accommodate additional demands
105
Pipe support spacing should be
Close enough together to prevent any appreciable SAG
106
In tubing fitting leaks, never take a chance if the flares not good you should
Cut it off and do it over
107
The best way to conduct plant maintenance is
With a plan maintenance program where all equipment is checked on a regular basis
108
Within pipe systems, excessive pressure results in
Accelerated where, possible overstressing, and premature failure of parts
109
Air control valves for industrial control circuits are
For the most part designed and built for use with pressures up to 150 psi
110
It is best to check the items on a maintenance login records at least once in the shift it is best to do this when
Early in the shift or at the beginning
111
Records of control valve and cylinder operating cycles are usually obtained from
Production records
112
Troubleshooting checks are determined by the
Type and number of components in the system
113
When locating trouble in a system, if there is air pressure in the supply , the sequence would
Start at the Air Supply and proceeded to the system actuator
114
Within the operations manual under general information, what is not in the system description and operation section
Troubleshooting procedures
115
When piston seals become worn and a leak check for leakage
by observing the exhaust ports
116
If the control valve action is sluggish, you must check
The moving parts for insufficient lubrication or swollen seals
117
Sheet generated during compression is controlled by
Limiting the pressure of the compressed air 
118
It’s a surrounding air around a cylinder is dusty or oily you must
Frequently clean with a detergent or steam
119
Valve wear of discharge valves is a result of?
Heat and accumulation of carbon deposits
120
In motor starting controls one way to check if the unloader is the problem you must
Let out all the air in the compressor reservoir and start the compressor again
121
Out of lubrication bearings and seals and intake valves, which maintenance item is not the same for all rotary compressions
Intake valves are not the same maintenance item
122
In troubleshooting controls, a control malfunction can best be isolated by
Analyzing the performance or lack of performance of the components and the pneumatic circuit
123
If there’s a loss of power in the pneumatic circuit, the system goes into
The system goes into manual
124
Solenoids are activated by
Ajit field set up by the flow of electrical current
125
If the valve has low air pressure, it can be shifted manually but
The circuit response may still not be correct
126
The use of improper lubricant in a control valve will not cause it to
Shift without a signal
127
Within a cylinder, tie rod cylinders are used mostly in
Industrial applications
128
This gland access the support or bearing for the piston rod as the travels back-and-forth during its work cycle
A bushing
129
Applications regarding a cylinder that involve higher temperatures or 200°F require
Special seals for the cylinder
130
Often improperly torqued which causes internal misalignment within the cylinder this is
Tie rod
131
The function of an internal cushion is to
Protect the cylinder from damage
132
When installing couplings on a hose, if the fitting is difficult, you must
Lubricate the nipple and the inside of the hose with a soapy solution
133
When you repair air motors or tools remember that they are precision built you must
Exercise care when disassembling and assembling them
134
The service life of air motors is limited unless
The air is clean, dry, and filtered
135
When inspecting a grinder gives special attention to
The arbor or motor shaft of an automatic grinder
136
Because of their slower operating speeds this air motor requires less maintenance than other air motors
Radial , piston air motors
137
The lower pressure in air oil tanks is overcome by
Relatively large work cylinders are required for anything except low output force
138
The main components in an air hydraulic booster, are it
Air, piston and hydraulic ram
139
Within single pressure booster systems, the manual shut off valve is used to
Adjust the oil levels between the make up tank and return tank as required
140
With an air oil cylinders possibility of air leakage is eliminated by
Placing a bleeder space or passage between the two sets of rod seals in the center of the unit
141
Another way of combining hydraulic and pneumatic systems is by interlocking their independent actions. The two independent systems are used for.
Economy and speed
142
But because the electric power sources do not always deliver their power output in a directly usable form , hydraulic systems
Convert electrical energy into usable energy
143
The function of a control valve in a system is
All of the above controls, the path controls the flow and controls the pressure
144
Fluid transmits hydraulic power through the system, but it also serves the important function of
Lubricating the hydraulic equipment
145
Before working on system, the first thing to understand is
The operation of the basic machine or system installed
146
In order for the system to provide correct hydraulic action, the valves and other components must be
Installed correctly
147
This diagram shows the general location, purpose, and appearance of the systems elements
A pictorial diagram
148
What illustrates the elements that make up a hydraulic system
All types of diagrams, pictorial, cutaway, and schematic diagrams illustrates the elements that make up a hydraulic system
149
These are used in a diagram to show the elements of the system shown as a device or a sign that stands for something
Schematic symbols
150
The first thing to do when reading a schematic of a hydraulic system is
Get the overall view of the system
151
The control valve symbol on a diagram, illustrates fluid flow and
Shows the valves function
152
Each major component in a hydraulic system has its own particular
Installation techniques that must be considered during installation
153
To provide proper alignment between pump and drive motor, this should be used
Flexible, coupling
154
You must jog the drive when starting a newly installed pump to
Make sure that rotation direction is correct before running the system
155
When hydraulic control valves are held together by bolts this is called
Manifold Ing only the four way valve is piped using this method
156
Which statement is not true about installing solenoids
Clipping off, the solenoid leads is not a good tip for installing solenoids
157
ForThe inlet piping of a pump, the diameter of the pipe should not be smaller than
The intake of the pump it should be larger
158
What considerations must be thought of while selecting tubing
All of the above the material ID and the wall thickness
159
Within tubing installations and bending tubing should not be assembled or connected in a straight line this is because
In the connection of tubing helps eliminate strain by absorbing vibration
160
The main advantage and disadvantage of using a hydraulic hose as it’s flexibility. These are also the reasons why
The hose wears out more rapidly than either pipe or tubing
161
Most seals used in hydraulic components, are designed engineers it is not your job to
Rectify to the design problems
162
The primary function of a hydraulic fluid is
To transmit efficiently, the force and energy
163
One of lubrications, most important properties of fluid are
It’s viscosity
164
Viscosity’s greatest item of affection is
Temperature
165
When selecting fluids for a system, you must make sure it is first
Compatible with the system
166
A precautionary step before filling a system with fluid you must make sure it is
Just make sure the system is clean
167
Time between inspections ,depends on other systems, and
The location of identical systems in the plant
168
Looking for possible troubles before they occur is preventative maintenance. Inspection is a form of.
Preventative maintenance
169
When A sample of fluid quality should be taken at in oil system is
Twice a year or every thousand hours
170
Repair being scheduled later should not be followed when
When safety is in line of production, never sacrifice safety for production
171
Reconditioning system is best to do when
The system has run for two years or breaks down
172
When troubleshooting listening to the pump is the only way of finding the problem because
A visual inspection is not possible until the pump has been disassembled
173
Pressure shocks in a positive displacement pump may cause other failures, such as
Repeated shaft, seal, blowout, broken rotor, segments, cracked, and broken veins and teeth
174
Excessive wear scratches or roughness in a gear pump means that
The system is compromised with solid contaminants
175
It is important that contaminants are kept out of the piston pumps because
They are manufactured with close tolerances
176
When any type of hydraulic pump is being repaired it is good general practice
Replace all anti-friction bearings, shaft seals and gaskets
177
Plasma performs what essential function when breaking a circuit
Allows flow between two open circuits
178
Protective feature a __________ is provided if gas pressure becomes to great in the chamber
Safety valve
179
True or false air blast breakers are greater than oil cooling breakers
True
180
An air circuit breaker employs air as the interrupting ______________
Insulation medium
181
Within circuit breaker controls a trip free operation occurs when the breaker is
Closed on a fault
182
The function of circuit breaker auxiliary contacts are to
Open first and close last
183
How is air for a breaker operation dried
By conducting it through automatic drying system
184
Transformers permit the transfer of electric energy between to circuits which are
Completely insulated from each other
185
In a transformer the winding that receives the voltage is called the
Secondary winding
186
Bushings are used on transformers to by
Insulating the leads and serve as entrances to the transformer
187
Transformers are classified as static or non static machines?
Static machines
188
When the secondary winding has more turns than the primary a greater voltage will be induced to the secondary and will be known as a
Step up transformer
189
To maintain the required primary current to supply the transformer losses and secondary load the transformer must have a
Balanced conditions
190
The input component of a hydraulic power transmission system is called a, the output is called
The input is called a pump and the output is called an actuator
191
The power source of a hydraulic system is a prime mover, such as
An electric motor or an engine
192
Which port limits the max PSI to the directional control valve
The inlet port
193
What pushes fluid into the pumping chamber to fill the void and charge the pump?
Atmospheric pressure
194
Pressure is generated in a hydraulic system by
The resistance of a load
195
In this mathematical formula with the variables, pressure force in area what is the equation?
Pressure equals force divided by area
196
Inlet pressure of a pump is usually measured in
Inches of mercury
197
Which parts of a hydraulic system is The rate at which work is performed is determined by
The pump and actuator
198
When Flo becomes turbulent in a pipe friction varies as
The square of the velocity
199
Work is done whenever a force or push is
Exerted through a distance
200
Because 1 gallon per minute of flow at one psi equals .000583 hp the total horsepower for any condition marks as
Horsepower equals gallons per minute times PSI times 0.000583
201
In the process of designing a simple hydraulic system, the first step should be
To select an actuator
202
To find the volume a cylinder will hold you must use this equation
Piston area times the stroke length
203
The turns ratio formula in transformers is
E1/E2=T1/T2
204
To find the secondary voltage or current given the primary windings specs you must use this formula
E2 x I2 = E1 x I1
205
Current transformers are instrument transformers used to
Step current down
206
The secondary terminal of a potential transformer should never be _________ to remove the device it operates from service
Short circuited
207
The secondary of a current transformer should never be _________ to remove the device it operates from
Opened
208
Transformers only having one winding are called
Autotransformers
209
In the core type transformer a section of both the primary and secondary windings are
Wound on each of the core
210
Hysteresis can be explained as
Friction of the molecules due to AC
211
True or false : iron losses occur in a transformer whenever the primary is energized , even though no load is on the secondary winding
True
212
The rating of a transformer is usually given in VA, KVA, or MVA
All of the above
213
Conservator systems are used on OCB transformers to
Preserve the dielectric strength of the transformer oil
214
A Hydrodynamic device uses kinetic energy rather than
Pressure
215
A hydrostatic device uses
Potential energy energy by pressure
216
The psi by height in feet is called
Feet of head of the column of water
217
A mercury barometer has the weight of the column of mercury with a perfect_____ at the top
Vacuum
218
Flow rate is the measure of volume of fluid, passing a point in a given time and can be measured by
Velocity
219
The flow rate and speed is a formula of
Gallons per minute equals cubed, inches divided by minutes
220
Laminar flow is
When particles of fluid move through a pipe in a street parallel flow path
221
Flow resistance or abrupt changes in cross-section upset the laminar flow and caused it to become
Turbulent
222
Verni’s principal states that if _______ is constant, the sum of kinetic energy and depress energy at various points in the system must be constant
Flow rate
223
In a hydraulic symbol, this is used to describe what carries fluid that is used to control the operation of a valve or other components
A pilot or sensing line it is written in long dashes
224
In hydraulic symbols, a motor is depicted as
A circle with a triangle pointing inward
225
Connecting lines are drawn to the bottom of the reservoir symbol when the lines
Terminate below the fluid level in the tank
226
What are the 4 primary purposes of hydraulic fluid systems
Cooling, lubricate, seal, transmission
227
In additional purposes of hydraulic fluid it must
Be compatible with compatible materials such as seals and hose interior linings
228
Other than sizes of clearances and pressure drop across the clearances what determines the leakage rate in a hydraulic system
The operating viscosity of the fluid
229
The viscosity of a fluid is defined as
Resistance to flow
230
Absolute viscosity is defined as
Resistance encountered when moving on layer of liquid over another
231
Kinematic viscosity is
The most common way way of measuring viscosity
232
Viscosity index is
A dimensionless number that characterizes the variation of viscosity of a fluid with variations of a temperature
233
Pour point is
Is the lowest temperature at which a fluid will flow
234
What is not a catalyst of oxidation pressure, water, agitation, or acids
Acid is not a catalyst for oxidation
235
These are additives that aid the fluid in the rejection of water
Demulsifiers
236
High specific gravity fluids used in a pump may be more critical in
Causing pump cavitation
237
Fire resistant oils are made up of
Water bases, and synthetics
238
Phosphate Esther attack
Elastomers some paints and plastic
239
The advantages of synthetic fluids are
Oxidation resistance, and high temperature operating characteristics
240
Pipe and pipe fittings are classified by ______ size and wall thickness
Nominal
241
The schedule number for standard pipe sizes
Schedule 40
242
One advantage of tubing over pipe is the ease of_____ to shape
Bending
243
Tubing sizes designated by
The outside diameter
244
Ceiling between sections of tubing is obtained by the use of various types of
Fittings
245
This dynamic seal is installed in an annual groove machine into one of the meeting parts
This is an O-ring
246
Lip type seals are used principally on these types of shafts
Rotating shafts
247
A rubber like material that contains no natural rubber is called a
Synthetic rubber or elastomer
248
This elastomer is a wide we use seal material in modern hydraulic systems and is inexpensive
Nitrile or Buna-N
249
Nitrile has a reasonably wide temperature range, which is
-40°F to 250°F
250
One of the several ways to reduce leakage is with the usage of
Mounted valves
251
Back mounting prefers to panel type installations where pipe or tubing is
Connected to sub plates
252
At two high temperature, a seal may ______ or swell
Soften
253
After installation, a seal began to wear quickly and leak, which meant it was probably not_______ before installation
Lubricated
254
The filler hole and a reservoir is provided with a
Opening that has a removable screen
255
A plate that prevents returning fluid from directly entering the pump inlet in a reservoir is called a
Baffle
256
Connections made on top of the reservoir often set______ to keep them above dirt and other contaminants
Risers
257
Lines that terminate near the tank bottom and are not equipped with strainers should be cut_________ prevent the line opening from bottoming in the tank and cutting off flow
A 45° angle
258
What is not one of the three most common standard reservoir, designs, flat top, L shaped, overhead stack, or wedge
Wedge is not one of the three most common standard reservoir designs
259
A modification on a reservoir to provide a reserve against unexpected demands on system capacity is
To size the reservoir for at least 20% over capacity
260
Fluids in a reservoir with a low viscosity index should be
Kept warm by heaters or heat exchangers
261
Reservoir temperature is controlled by
Heaters, air, coolers, and water coolers
262
Sources of contamination in a hydraulic system, R
Built-in contamination, ingress, contamination, and internally generated contamination 
263
Which of the following is not a mechanism of wear in hydraulic systems :adhesion ,filtration, fatigue ,cavitation
Filtration is not a mechanism of
264
A particle one micron in size equals______ inches
39 millionth of an inch
265
The smallest particle and I can see is approximately
40 µm
266
A contamination blockage which prevents the solenoid spool from shifting is called a
Transient failure
267
Hydraulic circuit components fail as a result of contamination and
Design
268
When sampling a hydraulic system the preferred location for sampling is directly _____ of the return line filter element
Upstream
269
To monitor initial and subsequent levels of contamination these points must be provided
Sample points must be provided
270
There are three areas hydraulic systems for locating a contamination control device
The pressure, return line, filter
271
The tubing must not be welded or
Brazed
272
When transferring clean oil the oil transfer pump must be equipped with a
5 micron filter
273
The term full flow applied to a filter means
That all the flow generated by the system passes through the filtering element
274
A coarse filter is referred to as a
Filter
275
The higher the mech or sieve number
The finer the screen
276
An increase in pressure difference across a filter will cause a
Increase in power consumption
277
To test for material compatibility with a filter element it is
Immersed for 72 hours in system fluid
278
When specifying the correct filter for a given application which of the following would not be considered
Flow sampling method
279
There are two basic classification of filtering materials and they are
Absorbent and adsorbent
280
What type of filter element provides precise control of pore size
Surface media
281
What is used to support the media again pressure differential in filters
Cylindrical perforated tubes
282
Hydraulic filter elements for fine filtration requirements are most frequently made of
Glass fiber material and also tend to have a pleated structure
283
This type of valve is incorporated into the housing to eliminate the possibility of element collapse or rupture in filters
A bypass valve
284
A filter designed to signal the operator when the element needs to be cleaned is a
Indicating filter
285
The double acting cylinder returns and extends by
Hydraulic pressure
286
Speed of cylinder formula
Gpm x (231/effective piston area)
287
Force of cylinder formula
Force = PSI x in^2
288
Pressure of a cylinder formula
PSI = force(lbs) / piston area (in^2)
289
Displacement in hydraulic actuators is
The amount of fluid required to turn the motor output shaft one revolution
290
Torque rate in a motor formula =
Torque load(lb-in)/desired operating psi x0.01
291
Which motor is Not classified by application
HSLT, LSHT , torque actuators , or LMPG
292
Internal gear motors fall into two categories
Direct drive gerotor and orbiting gerotor
293
Balnced motors vanes are held against the cam ring by
System pressure
294
In vane motors inlet fluid is also ported under the vanes so as to
Balance the pressure between the top and bottom
295
Devices which usually cannot rotate continuously in one direction are
( both a and c) torque generator and actuator
296
Torque is proportional to the area of the pistons and is a function of the angular relationship at wich
The swash plate is positioned
297
Motor displacement is varied in response to workload changes by
The compensator control
298
A hydraulic motor that rotates less than a full revolution is sometimes called
A limited rotation actuator
299
This valves control the direction of fluid flow
Directional valves
300
These valves direct the fluid by opening and closing flow paths in discrete valve spool positions
Definite position directional finite valves
301
This valve allows free flow in one direction and blocks flow in the other direction
Check valve
302
A heavy spring check valve is usually correlated as a
Relief valve
303
This valve is normally offset to one extreme position by a spring , it has one actuator that shifts the spool to the other extreme position
Two position spring offset
304
Directional valves are not
Actuators
305
Directional control valves may be shifted
All of the above
306
The pilot pressure on a two stage valve may be supplied by
An internal or external passage
307
To control the shift speed of the main spool on a two stage valve
A pilot choke may be incorporated
308
To increase the shifting speed on a two stage valve a
Pilot piston can be used
309
A simple method on a two stage valve of flow control that restricts the distance the main spool can shift is
A spool stroke limiter
310
Line mounted versions of spool stroke limiters are more frequently found in 
Mobile applications
311
A typical deceleration valve application is
Too slow a drill, head from fast advance to feed speed
312
This valve loses control in reverse flow rate that is permitted by the integral check valve
A tapered, plunger design deceleration valve
313
What type of deceleration valve allows the load to creep?
A window or fist valve
314
In a prefall valve, what pushes the fluid through the valve?
Atmospheric pressure or gravity
315
Decompression valves are offered as an integral part of of the pre-fill valve that
Prevent possible damage from hydraulic shock
316
A relief valve is normally closed or normally opened
Normally closed
317
What is a relief valves purpose?
To limit pressure in the system to a preset maximum
318
The pressure at which the valve first begins to divert flow is called the
Cracking pressure
319
The difference between cracking pressure and full flow pressure is sometimes called
Pressure override
320
The event connection to the chamber above the piston vents to
The tank
321
To use the same valve as an unloading valve you need
Back pressure
322
A back pressure valve operates in
Balance
323
A sequence valve is used to cause actions to take place in a system in
A definite order
324
If a sequence valve is installed downstream in a cylinder line , it must have a
Check valve to allow free flow return
325
The pressure setting in a counterbalance valve is slightly higher than
Is required to hold the load from falling
326
A brake valve is used in the exhaust line of a hydraulic motor to
Prevent over speeding and to prevent excessive pressure buildup when decelerating
327
When the load is being accelerated, pressure is
Maximum at the motor inlet
328
To control the flow when a load tends to run away the best approaches to
Utilize a meter out circuit
329
A flow control valve purposes
To control the rate of flow
330
A meter in circuit is
A circuit that controls the amount of fluid going into the actuator
331
Another method of controlling flow that is installed in a branch circuit off the main line to control cylinder speed is
A bleed off circuit
332
By adjusting the flow control on a bleed off circuit
The pump delivery is diverted to the reservoir and affects the cylinder speed
333
On a bypass type for control the spring that keeps the bypass piston close is equivalent to
20 psi
334
On a restricted type for control, a 20 psi spring holds the compensator spool and the normally_______ position
Open
335
The use of any type of proportional valve requires that the equipment contain
Electrical power supply
336
These type of valves are restricted type flow controls, and they are usually used in a meter out configuration
Deceleration valves
337
Displacement in a hydraulic pump is the
Max or pressure capability output in GPM
338
Displacement is expressed in
Cubic inches per revolution or CIR cubed
339
Efficiency percentage in a hydraulic pump formula is
The efficiency percentage equals the actual output times 100 divided by the theoretical output
340
Fix displacement pumps have a displacement that cannot be changed without
Replacing some internal components of the pump
341
Because gear pumps have higher pressures at pump outlets, and lower pressures at pump inlet they referred to as
An unbalanced design
342
Most fixed displacement vein pumps use
A balanced design
343
On an intra-vein pump holes drilled through the rotor segments act as this purpose
Equalize pressure above and below
344
An axial piston pumps, the pistons reciprocate_____ to the axis of rotation of the cylinder block
Parallel
345
On a bent axis piston pump, the connection from the driveshaft to the cylinder block causes
A angle
346
On in-line piston pumps, the pistons fitted to boards in the cylinder block are connected through
Piston shoes
347
Accumulators provide a way to store fluids
Under pressure
348
The energy storage capability also makes accumulators capable of acting as
Shock absorber
349
A weight loaded accumulator is the only type of accumulator where pressure is______ whether the chamber is full or nearly empty
Constant
350
The most commonly used gas in a gas charged accumulator is
Nitrogen
351
The pre-charge on a gas charge accumulator should never be less than
1/4 of the maximum working pressure
352
An intensifier on a cylinder is a device used to
Multiply pressure
353
A push rod operates two electrical switches by
Using a plunger to press both electricals switches
354
Two principal types of pressure gauges are
The Borden tube and the Schrader type
355
Vacuum gauges are calibrated in
Inches of mercury
356
The purpose of a snubber on gauges are
To prevent the gauge from oscillating and protects it from pressure surges
357
Name all types of chemical hazards
Flammable, explosive, toxic, and corrosive
358
The four main types of hazards are
Electrical, chemical, mechanical, and environmental
359
Most common work place injuries are
Back injuries
360
An example of a contact by accident is
A splash from a chemical
361
When encountering a chemical spill only pick it up if
You are trained to handle it
362
If you see a way to make your job safer you should tell your
Supervisor
363
OSHA’s hazard communication standard states about flammable chemicals
Chemical manufacturers and distributors to classify chemicals that are flammable
364
The purpose of the EPA
Control chemicals in the environment
365
Chemical glove manufactures test gloves extensively to show
Which gloves protect against with chemicals
366
The best eye protection better than safety glasses are
Safety goggles
367
The second kind of atmosphere supplying respirator is
SCBA self contained breathing apparatus
368
Which of the following is the responsibility of an employee
Identifying ppe to be worn on the job
369
While using mechanical tools or rotary tools you must not wear
Gloves
370
While using an electrical tool if a short circuit occurs what becomes part of the circuit
The handle or casing
371
Before you disconnect a pneumatic tool you must first
Relieve the pressure
372
Before you disconnect a pneumatic tool you must first
Relieve the pressure
373
To use a forklift you must be
OSHA certified
374
Under what conditions is it safe to stand under a load
Never
375
The fixed guard opening can be as large as 6 in if
It’s more that 3ft from the operation
376
If the machine is equipped with presence sensing guards
There is no physical barrier between the operator and danger zone
377
In tagout osha requires that tags should never be
Bypassed or ignored
378
Potential difference is measured in
Volts
379
I’m a properly wired 120 v circuit the hot wire is ______ and the neutral is_____
Generally black or red, white or gray
380
If you touch someone who is in contact with an electrical source you will
Also become part of the circuit
381
The most common method of preventing the accumulation of static electricity is
Grounding
382
Fuses and circuit breakers are designed to act as ______ to prevent them from overloading
Safety valves
383
If the unexpected start up of equipment is likely to danger people, power to the equipment must be
Locked out
384
In a fire pyramid these three elements will give you a chain reaction
Oxygen, fuel , heat
385
A class B fire are of flammable or combustible
Liquids and gasses
386
Water puts out fire by
Reducing the temperature of the fuel
387
After using this type of fire extinguisher it must be turned in for refilling
Pump tank water
388
Ultraviolet radiation from welding can
Damage the eyes as well as produce a burn similar to sunburn
389
One of the most important safety concerns for workers in confined spaces is the
Atmosphere within the space
390
The warning signs of heatstroke are
Hot and dry skin , severe headache, rapidly rising temperature, fainting
