True/False
Indicate whether the
statement is true or false.
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1.
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Meter-in means the flow rate into the acuator is being controlled, while the
meter-out means the flow rate out of the actuator is being controlled.
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2.
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Meter-out is prefered in pneumatics because it helps smooth out the jumpy
movement of the acuators.
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3.
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A dryer is not necessary in a pneumatic system because condensation is desirable
for lubriation of the air in the system.
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4.
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Refrigeration dryers compress and heat air, then expand and cool air to alter
the pressure dew point of the air.
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5.
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Absorption dryers use a gel material to absorb water as it passes through
it.
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6.
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Water vapor exist in pneumatic systems as water vapor and liquid water, both of
which are desirable for an effective system.
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7.
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It is easy to accurately predict the speed of a pneumatic cylinder because of
the compressibility of air.
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8.
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The speed of a pneumatic cylinder depends on the supply pressure and
load.
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Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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9.
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All of the following are considered advantages of using pneumatic motors over
electric motors EXCEPT:
a. | Pneumatic motors can stall under full load for indefinite periods of
time | c. | Pneumatic motors tend to be less expensive than electric motors | b. | Pneumatic motors can
be used in areas where a fire hazard would exist with electric motors | d. | Pneumatic motors are much heavier than electric
motors, giving them higher range in load capability |
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10.
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All of the following devices make up a FRL unit EXCEPT:
a. | flow device | c. | lubricator | b. | filter | d. | regulator |
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Matching
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a. | shuttle valve | f. | pressure regulator | b. | exhaust valve | g. | starting torque | c. | running
torque | h. | dew
point | d. | AND valve | i. | relative humidity | e. | stall torque |
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11.
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Used to increase cylinder speed by speeding up the exhaust flow out of the
cylinder.
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12.
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Used to adjust the supply of pressure to an appropriate level for a particular
machine.
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13.
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A way to measure the amount of moisture in the air; reads the temperature at
which air becomes saturated with water.
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14.
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Allows flow from either of two inlets to be sent to a common/single outlet; OR
valve.
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15.
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The percentage of water in the air as compared to the maximum amount it could
hold.
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16.
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Torque required to stop a rotating motore at a particular supply pressure.
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17.
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Torque generated when the motor is rotating at a particular speed.
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18.
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Requires pressure at both inlet ports simultaneously for flow to be sent to the
outlet.
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19.
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Torque generated when a motor is started from dead stop under load.
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a. | 2026 , 1822 | e. | 393 , 368 | b. | 1190 | f. | 35.4 | c. | 1.90
| g. | 12.23 | d. | 0.0296
| h. | 1.57
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20.
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A double acting pneumatic cylinder with a 2.5 in bore and a 0.625 in rod is to
be used in a system with a supply pressure of 80 psig. What is the force output of the cylinder on
the extend and retract stroke?
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21.
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A double acting pneumatic cylinder with a 63 mm bore and a 20 mm rod is to be
used in a system with a supply pressure of 650 kPa. What is the force output of the cylinder on the
extend and retract stroke?
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22.
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A double acting pneumatic cylinder with a 2.5 in bore, a 1 in rod, and a 5 in
stroke length must cycle (extend and retract) 60 times per minute. The supply pressure is 100 psig.
What is the air consumption of the cylinder in scfm?
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23.
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A double acting pneumatic cylinder with a 63 mm bore, a 20 mm rod, and a 120 mm
stroke length must cycle (extend and retract) 60 times per minute. The supply pressure is 600 kPa
guage. What is the air consumption of the cylinder in standard m3/mim?
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24.
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An air-powered machine consumes 40 scfm at 80 psig. If the directional control
vavle that will control this machine can have a pressure drop of no more than 5 psi, what is the
minimum Cv? Assume the temperature of the air is 80°F.
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25.
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An air-powered machine consumes 1000 lpm at 50 kPa. If the directional control
vavle that will control this machine can have a pressure drop of no more than 40 kPa, what is the
minimum Cv? Assume the temperature of the air is 30°C.
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26.
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A valve with a Cv of 1.2 is used in a system with a supply pressure
of 80 psig. The pressure drop across the valve is 10 psi. What is the flow through the valve? Assume
the temperature of the air is 90°F.
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27.
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A valve with a Cv of 1.35 is used in a system with a supply pressure
of 600 kPa. The pressure drop across the valve is 70 kPa. What is the flow through the valve? Assume
the temperature of the air is 25°C.
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28.
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4-way, 2-position, push button
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29.
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4-way, 3-position, closed center
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30.
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3-way, 2 position, push button
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31.
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5-way, 2-position, solenoid acuated
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32.
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2-way, 2-position, push button
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33.
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3-position spring centered
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34.
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4-way, 3 position, float center
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