ITMC Hydraulic Systems 2 β Questions and Answers
Question 1: What does a hydraulic accumulator primarily store?
- Hydraulic fluid under pressure (Correct answer)
- Electrical energy
- Compressed air only
- Mechanical spring tension
Correct answer: Hydraulic fluid under pressure
A hydraulic accumulator stores hydraulic fluid under pressure to supplement pump flow or absorb pressure shocks.
Question 2: Which type of hydraulic pump is considered a fixed-displacement pump?
- Gear pump (Correct answer)
- Variable piston pump
- Vane pump with pressure compensator
- Bent-axis variable pump
Correct answer: Gear pump
Gear pumps deliver a fixed volume of fluid per revolution and cannot vary their displacement.
Question 3: A hydraulic system is operating at 3,000 PSI with a cylinder bore of 2 inches. What is the approximate force output?
- 9,425 lbf (Correct answer)
- 6,000 lbf
- 12,000 lbf
- 3,000 lbf
Correct answer: 9,425 lbf
Force = Pressure Γ Area; Area = Ο Γ rΒ² = Ο Γ 1Β² β 3.14 inΒ²; Force = 3,000 Γ 3.14 β 9,425 lbf.
Question 4: What is the purpose of a hydraulic flow control valve?
- Regulate the speed of actuators (Correct answer)
- Limit maximum system pressure
- Prevent backflow in the circuit
- Filter contaminants from fluid
Correct answer: Regulate the speed of actuators
Flow control valves regulate the rate of fluid flow to control the speed of hydraulic actuators.
Question 5: Which hydraulic seal material is most resistant to petroleum-based hydraulic fluids?
- Nitrile (Buna-N) (Correct answer)
- Silicone
- Natural rubber
- Neoprene
Correct answer: Nitrile (Buna-N)
Nitrile rubber is the standard seal material for petroleum-based hydraulic systems due to its excellent oil resistance.
Question 6: What condition is indicated when a hydraulic pump produces a whining or cavitation noise?
- Insufficient fluid supply to the pump inlet (Correct answer)
- Excessive back pressure on the return line
- Clogged pressure relief valve
- Overheating of hydraulic fluid
Correct answer: Insufficient fluid supply to the pump inlet
Cavitation occurs when the pump inlet is starved of fluid, causing vapor bubbles to form and collapse violently.
Question 7: In a hydraulic schematic, what symbol represents a pressure relief valve?
- An arrow pointing into a line with a spring symbol (Correct answer)
- A circle with an X through it
- A diamond shape with directional arrows
- A rectangle with a sliding element
Correct answer: An arrow pointing into a line with a spring symbol
Pressure relief valves are shown with a normally-closed arrow symbol with a spring, indicating they open at a set pressure.
ITMC Hydraulic Systems 2
What does a hydraulic accumulator primarily store?