Pneumatics Troubleshooting C304 Exam Questions and Answers Latest Update 2025-2026
Flow rate measurements are taken using special devices like pilot tubes, orifice plates, and
__________. - Answers Rotameters
A ___________ is the malfunction you observe in pneumatic system caused by a fault. - Answers
Symptom
A complete lockout/tagout program requires that _______ `be locked out for servicing or
maintenance - Answers All power sources
To perform an out-of-circuit test, a component can be placed on a __________ to provide a basic
circuit to test the component - Answers Test bench
Inserting a pressure gauge into the pneumatic system using a tee creates a test station or
__________. - Answers Test point
When you first approach a pneumatic system that requires troubleshooting, take the time to
___________ the entire system. - Answers Visually inspect
When working around pneumatic equipment you should ________. - Answers Remove any rings
________________ level troubleshooting is the process of determining what failed inside a
particular component - Answers Component
A lockout valve is a two-position valve that in its closed position blocks the supply line and
____________ downstream air pressure. - Answers Vents
Before you remove pressure from the system, you should ____________. - Answers Support any
overrunning loads
When performing an electrical lockout/tagout, the last thing the worker should do is
____________. - Answers Test the locked out equipment for power
A partially blocked air filter can cause an actuator to ____________. - Answers Move slowly
If a non-venting regulator is used to replace a venting regulator, the result may be __________. -
Answers Higher pressure
A pressure drop measured across a filter indicates a ___________. - Answers Dirty filter element
The first step in troubleshooting a pneumatic system is to ____________. - Answers Identify the
symptoms
Delayed oil delivery from a lubricator is probably the result of a misadjustment or a
______________. - Answers Partially clogged pick-up tube
A lubricator that is supplying too much oil to the system can be noticed by __________. - Answers
, Oil drips at the exhaust ports of components
A sludge collector is used in a pneumatic system to ____________. - Answers Trap rust, dirt, and
other contaminants
A noisy regulator may be caused by ___________. - Answers Air escaping from the vent port
Flow control valves are used to control actuator speed and ______________________. - Answers
Sequence timing
Rotary actuator speed is determined by the _____________ between the two ports. - Answers
Differential pressure
Rotary actuators have a range of motion of ____________ degrees or less - Answers 280
A DCV spool that will not return to its neutral position may be the result of a broken ___________.
- Answers Return spring
Cylinder drift can be caused by _____________. - Answers Leakage
Actuator drift is a symptom that a QEV's _________. - Answers Gasket is improperly sealed
The __________ of a rotary actuator contains the inlet and outlet ports. - Answers Head
A cylinder that has fast speed may be the result of ____________. - Answers A decrease in load
The __________ can be used to determine if the DCV's spool is stuck or if the solenoid is not
working. - Answers Manual override
The ________ is used to control the pilot plunger's movement in a pilot-operated DCV - Answers
Solenoid coil
A decrease in flow through a flow control valve can be caused by _____________. - Answers A
blocked port
QEVs boost an actuator's cycle speed by __________________. - Answers Exhausting directly to
atmosphere
____________ is a symptom of loose fittings on a rotary actuator"s ports. - Answers External
leakage
NPN switches should be used ____________. - Answers When the PLC provides electrical power
An uneven part surface can cause a vacuum cup to lose its seal because __________. - Answers
It allows air to enter the cup reducing the amount of vacuum
An oversized vacuum cup ________ a thin part. - Answers May damage
Flow rate measurements are taken using special devices like pilot tubes, orifice plates, and
__________. - Answers Rotameters
A ___________ is the malfunction you observe in pneumatic system caused by a fault. - Answers
Symptom
A complete lockout/tagout program requires that _______ `be locked out for servicing or
maintenance - Answers All power sources
To perform an out-of-circuit test, a component can be placed on a __________ to provide a basic
circuit to test the component - Answers Test bench
Inserting a pressure gauge into the pneumatic system using a tee creates a test station or
__________. - Answers Test point
When you first approach a pneumatic system that requires troubleshooting, take the time to
___________ the entire system. - Answers Visually inspect
When working around pneumatic equipment you should ________. - Answers Remove any rings
________________ level troubleshooting is the process of determining what failed inside a
particular component - Answers Component
A lockout valve is a two-position valve that in its closed position blocks the supply line and
____________ downstream air pressure. - Answers Vents
Before you remove pressure from the system, you should ____________. - Answers Support any
overrunning loads
When performing an electrical lockout/tagout, the last thing the worker should do is
____________. - Answers Test the locked out equipment for power
A partially blocked air filter can cause an actuator to ____________. - Answers Move slowly
If a non-venting regulator is used to replace a venting regulator, the result may be __________. -
Answers Higher pressure
A pressure drop measured across a filter indicates a ___________. - Answers Dirty filter element
The first step in troubleshooting a pneumatic system is to ____________. - Answers Identify the
symptoms
Delayed oil delivery from a lubricator is probably the result of a misadjustment or a
______________. - Answers Partially clogged pick-up tube
A lubricator that is supplying too much oil to the system can be noticed by __________. - Answers
, Oil drips at the exhaust ports of components
A sludge collector is used in a pneumatic system to ____________. - Answers Trap rust, dirt, and
other contaminants
A noisy regulator may be caused by ___________. - Answers Air escaping from the vent port
Flow control valves are used to control actuator speed and ______________________. - Answers
Sequence timing
Rotary actuator speed is determined by the _____________ between the two ports. - Answers
Differential pressure
Rotary actuators have a range of motion of ____________ degrees or less - Answers 280
A DCV spool that will not return to its neutral position may be the result of a broken ___________.
- Answers Return spring
Cylinder drift can be caused by _____________. - Answers Leakage
Actuator drift is a symptom that a QEV's _________. - Answers Gasket is improperly sealed
The __________ of a rotary actuator contains the inlet and outlet ports. - Answers Head
A cylinder that has fast speed may be the result of ____________. - Answers A decrease in load
The __________ can be used to determine if the DCV's spool is stuck or if the solenoid is not
working. - Answers Manual override
The ________ is used to control the pilot plunger's movement in a pilot-operated DCV - Answers
Solenoid coil
A decrease in flow through a flow control valve can be caused by _____________. - Answers A
blocked port
QEVs boost an actuator's cycle speed by __________________. - Answers Exhausting directly to
atmosphere
____________ is a symptom of loose fittings on a rotary actuator"s ports. - Answers External
leakage
NPN switches should be used ____________. - Answers When the PLC provides electrical power
An uneven part surface can cause a vacuum cup to lose its seal because __________. - Answers
It allows air to enter the cup reducing the amount of vacuum
An oversized vacuum cup ________ a thin part. - Answers May damage
