Pneumatic and Hydraulic Systems Flashcards
7 cards from real SACA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Pneumatic and Hydraulic Systems flashcards as text
In a hydraulic system, what is the primary purpose of a pressure relief valve?
Answer: To protect the system from overpressure by diverting excess fluid to tank
A pressure relief valve protects hydraulic circuits by opening and diverting fluid back to the reservoir when system pressure exceeds a preset limit.
Which type of hydraulic pump is most commonly used in industrial automation systems due to its variable displacement capability?
Answer: Piston pump
Piston pumps are preferred in industrial automation because they offer variable displacement, high efficiency, and can operate at high pressures.
A pneumatic system uses a 5/2 directional control valve. What do the numbers 5 and 2 represent?
Answer: 5 ports and 2 switching positions
In pneumatic valve nomenclature, the first number indicates the number of ports and the second indicates the number of switching positions.
What is cavitation in a hydraulic pump, and what causes it?
Answer: Formation and collapse of vapor bubbles due to localized low pressure at the inlet
Cavitation occurs when the pump inlet pressure drops below the fluid's vapor pressure, causing vapor bubbles that implode violently and damage pump components.
In a pneumatic circuit, a flow control valve with a check valve bypass is used to control actuator speed. Which function does this configuration perform?
Answer: Meter-out control — restricts exhaust flow leaving the actuator
A flow control valve with a bypass check valve provides meter-out control by restricting exhaust air while allowing free flow in the supply direction.
What is the function of a hydraulic accumulator in an automation system?
Answer: To store pressurized fluid for supplementing pump flow during peak demand
Hydraulic accumulators store pressurized fluid energy and release it during peak demand cycles, reducing pump size requirements and smoothing pressure fluctuations.
In pneumatic systems, what does the ISO symbol for an FRL unit represent?
Answer: Filter-Regulator-Lubricator — conditions compressed air for downstream use
An FRL (Filter-Regulator-Lubricator) unit conditions compressed air by removing contaminants, regulating pressure, and adding lubrication for pneumatic components.