Hydraulic Systems & Pneumatics Flashcards
7 cards from real OECP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Hydraulic Systems & Pneumatics flashcards as text
What is the primary advantage of pneumatic systems over hydraulic systems for many construction site applications?
Answer: Pneumatic systems are cleaner and simpler because exhaust air vents harmlessly to atmosphere
Pneumatic systems use compressed air that exhausts directly to atmosphere after doing work, eliminating return lines and fluid disposal concerns, making them cleaner and simpler than hydraulic systems.
What is the typical operating pressure range for industrial pneumatic systems and pneumatic tools used in construction?
Answer: 80–150 PSI
Industrial pneumatic systems typically operate at 80–150 PSI, which is the standard output range of construction air compressors and is sufficient to power pneumatic tools and actuators safely.
What is the purpose of an FRL (Filter-Regulator-Lubricator) unit installed in a pneumatic supply line?
Answer: To condition compressed air by removing contaminants, setting pressure, and adding lubrication
An FRL unit treats compressed air by filtering moisture and particles, regulating pressure to the required tool rating, and adding a fine mist of oil to lubricate internal air-powered tool components.
What is the primary hazard when using compressed air tools and equipment on a construction site?
Answer: High-velocity air injection injuries and projectile particles striking workers
Compressed air at even moderate pressure can penetrate skin and cause fatal air embolism if directed at the body, and can launch particles at lethal velocity, making air-directed horseplay strictly prohibited.
What causes moisture buildup inside compressed air lines and pneumatic tools during normal operation?
Answer: Water vapor present in atmospheric air that condenses as compressed air cools in the lines
Atmospheric air contains water vapor that concentrates when compressed; as the air cools downstream in hoses and tools, the water vapor condenses into liquid, causing moisture accumulation throughout the pneumatic system.
What is the correct procedure for safely disconnecting a pneumatic tool or hose from an air supply line?
Answer: Shut off the air supply valve, bleed residual line pressure, then disconnect the fitting
Safe disconnection requires closing the supply valve first, then bleeding residual pressure from the hose before disconnecting, to prevent sudden uncontrolled air release or hose whipping.
What does dew point indicate when evaluating the quality of compressed air in a pneumatic system?
Answer: The temperature at which water vapor in the compressed air will condense into liquid
Dew point is the temperature at which moisture in compressed air reaches saturation and condenses; a lower dew point indicates drier air, which reduces corrosion, tool wear, and freeze-ups in cold weather.