Ramsay Test Ramsay Hydraulics & Pneumatics 4 — Questions and Answers
Question 1: A hydraulic cylinder is extending slower than normal despite correct pump flow. What is the MOST likely cause?
- Excessive back pressure in the return line (Correct answer)
- Low reservoir fluid level causing cavitation
- Incorrect cylinder bore size
- Faulty pressure gauge reading
Correct answer: Excessive back pressure in the return line
Excessive back pressure in the return line restricts fluid from leaving the rod end, slowing the extension stroke.
Question 2: In a pneumatic system, a lubricator is placed in the air line to:
- Remove water vapor from compressed air
- Add oil mist to lubricate downstream components (Correct answer)
- Regulate air pressure to actuators
- Filter particulates from the air supply
Correct answer: Add oil mist to lubricate downstream components
A lubricator introduces a fine oil mist into the air stream to reduce wear on valves, cylinders, and other moving components.
Question 3: Which type of hydraulic valve controls the RATE of fluid flow to an actuator?
- Pressure relief valve
- Check valve
- Flow control valve (Correct answer)
- Directional control valve
Correct answer: Flow control valve
A flow control valve meters the volume of fluid passing through it, directly determining the speed of the actuator.
Question 4: A double-acting pneumatic cylinder requires air to:
- Only one port to extend and retract via spring return
- Both ports alternately to extend and retract under power (Correct answer)
- Both ports simultaneously to hold position
- Neither port when load holds the piston stationary
Correct answer: Both ports alternately to extend and retract under power
A double-acting cylinder uses compressed air applied to alternate ports to produce powered motion in both directions.
Question 5: Hydraulic fluid viscosity that is TOO LOW will most likely cause:
- Excessive heat buildup in pump
- Increased internal leakage past seals and pump clearances (Correct answer)
- Higher system pressure than desired
- Sluggish actuator response
Correct answer: Increased internal leakage past seals and pump clearances
Thin (low-viscosity) fluid slips past internal clearances and seals, reducing volumetric efficiency and causing internal leakage.
Question 6: What does the term 'CFM' refer to in a pneumatic system?
- Centrifugal force measurement
- Cubic feet per minute — a measure of air flow volume (Correct answer)
- Compressor force multiplier
- Cylinder force multiplier
Correct answer: Cubic feet per minute — a measure of air flow volume
CFM (cubic feet per minute) is the standard US unit for measuring volumetric air flow rate in pneumatic systems.
Question 7: In a hydraulic system, an accumulator is used to:
- Convert mechanical energy to hydraulic energy
- Store hydraulic energy and dampen pressure spikes (Correct answer)
- Filter contaminants from hydraulic fluid
- Control the direction of actuator movement
Correct answer: Store hydraulic energy and dampen pressure spikes
An accumulator stores pressurized fluid (using gas precharge) to supplement pump flow on demand and absorb pressure surges.
Ramsay Test Ramsay Hydraulics & Pneumatics 4
A hydraulic cylinder is extending slower than normal despite correct pump flow.
What is the MOST likely cause?