South Carolina Compressed Air Systems
Technician Certification License Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. A technician is troubleshooting a rotary screw compressor that is
overheating. Which of the following is the MOST likely cause?
A. Excessive inlet air filtration
B. Insufficient cooling airflow
C. High lubricant viscosity
D. Lower than normal discharge pressure
Inadequate cooling airflow prevents proper heat dissipation, causing the
compressor to overheat.
2. What is the purpose of a dryer in a compressed air system?
A. To increase air pressure
B. To remove moisture from compressed air
C. To add lubrication to the air stream
D. To cool the compressor motor
Dryers are designed to remove water from compressed air to prevent
corrosion and contamination.
3. Which component is critical for preventing liquid carryover into
downstream equipment?
, A. Check valve
B. Pressure gauge
C. Aftercooler
D. Unloader valve
Aftercoolers reduce air temperature, condensing moisture before it enters
the system, minimizing liquid carryover.
4. In a compressed air system, what does SCFM stand for?
A. Standard Cubic Feet per Minute
B. System Compressed Fluid Measurement
C. Standard Cubic Feet per Minute
D. Sustained Compressed Flow Metric
SCFM is the standardized measurement of airflow used to compare
compressor capacities.
5. What is the PRIMARY hazard associated with high-pressure
compressed air?
A. Electrical shock
B. Injection injury
C. Noise pollution
D. Vapor inhalation
High-pressure air can penetrate skin and cause serious injection injuries.
6. Which device protects a compressor from excessive pressure build-up?
A. Solenoid valve
B. Flow restrictor
C. Safety relief valve
D. Check valve
Safety relief valves open at a set pressure to prevent over-pressurization.
, 7. What does a pressure dew point indicate?
A. Maximum operating temperature
B. Compressor oil viscosity
C. Temperature at which moisture condenses
D. Electrical consumption rate
Pressure dew point is the temperature where compressed air moisture
condenses at system pressure.
8. Why is it important to drain condensate from receiver tanks regularly?
A. To reduce noise
B. To increase temperature
C. To prevent corrosion and water contamination
D. To reduce oil viscosity
Regularly draining condensate prevents water build-up that causes
corrosion and contamination.
9. A compressor’s interstage cooler is installed to:
A. Increase discharge pressure
B. Reduce oil carryover
C. Lower the temperature between compression stages
D. Bypass moisture removal
Interstage coolers reduce air temperature to improve efficiency and protect
components.
10. Which lubricant property is MOST important for compressor
bearings?
A. Color
B. Flash point
C. Viscosity
D. Odor
Viscosity determines the oil’s ability to lubricate moving parts properly.
Technician Certification License Exam
Practice Questions And Correct Answers
(Verified Answers) Plus Rationale 2026
Q&A| Instant Download Pdf
1. A technician is troubleshooting a rotary screw compressor that is
overheating. Which of the following is the MOST likely cause?
A. Excessive inlet air filtration
B. Insufficient cooling airflow
C. High lubricant viscosity
D. Lower than normal discharge pressure
Inadequate cooling airflow prevents proper heat dissipation, causing the
compressor to overheat.
2. What is the purpose of a dryer in a compressed air system?
A. To increase air pressure
B. To remove moisture from compressed air
C. To add lubrication to the air stream
D. To cool the compressor motor
Dryers are designed to remove water from compressed air to prevent
corrosion and contamination.
3. Which component is critical for preventing liquid carryover into
downstream equipment?
, A. Check valve
B. Pressure gauge
C. Aftercooler
D. Unloader valve
Aftercoolers reduce air temperature, condensing moisture before it enters
the system, minimizing liquid carryover.
4. In a compressed air system, what does SCFM stand for?
A. Standard Cubic Feet per Minute
B. System Compressed Fluid Measurement
C. Standard Cubic Feet per Minute
D. Sustained Compressed Flow Metric
SCFM is the standardized measurement of airflow used to compare
compressor capacities.
5. What is the PRIMARY hazard associated with high-pressure
compressed air?
A. Electrical shock
B. Injection injury
C. Noise pollution
D. Vapor inhalation
High-pressure air can penetrate skin and cause serious injection injuries.
6. Which device protects a compressor from excessive pressure build-up?
A. Solenoid valve
B. Flow restrictor
C. Safety relief valve
D. Check valve
Safety relief valves open at a set pressure to prevent over-pressurization.
, 7. What does a pressure dew point indicate?
A. Maximum operating temperature
B. Compressor oil viscosity
C. Temperature at which moisture condenses
D. Electrical consumption rate
Pressure dew point is the temperature where compressed air moisture
condenses at system pressure.
8. Why is it important to drain condensate from receiver tanks regularly?
A. To reduce noise
B. To increase temperature
C. To prevent corrosion and water contamination
D. To reduce oil viscosity
Regularly draining condensate prevents water build-up that causes
corrosion and contamination.
9. A compressor’s interstage cooler is installed to:
A. Increase discharge pressure
B. Reduce oil carryover
C. Lower the temperature between compression stages
D. Bypass moisture removal
Interstage coolers reduce air temperature to improve efficiency and protect
components.
10. Which lubricant property is MOST important for compressor
bearings?
A. Color
B. Flash point
C. Viscosity
D. Odor
Viscosity determines the oil’s ability to lubricate moving parts properly.
