Simple Hydraulic System Diagram Quiz

Find 18 parts of a basic hydraulic circuit by name: the power unit first, then the valves, cylinder and motor.

Simple Hydraulic System Diagram Quiz

Name Date

Tap the reservoir

1 of 10

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Write the name of each numbered part.Answer key

  1. Reservoir
  2. Air vent (breather)
  3. Baffle
  4. Strainer
  5. Pump
  6. Electric motor
  7. Pressure line
  8. Relief valve
  9. Pressure gauge
  10. Filter
  11. Check valve
  12. Accumulator
  13. Directional control valve
  14. Hoses
  15. Cylinder
  16. Hydraulic motor
  17. Return line
  18. Cooler

Drawn for this site on 2026-09-30 from plain geometry. Licence: own work.

Each numbered ring is a button. Use the arrow keys to move between them and Enter to choose. Names are read out in Study, and once a part is answered.

Next step Read every name on the labeled hydraulic system

All 18 parts on the diagram

Show the list

The power unit 10

  1. Reservoir It also lets air bubbles escape and dirt settle to the bottom. It gives off heat from the oil.
  2. Air vent (breather) Air moves through it as the oil level goes up and down. That keeps the space above the oil at the pressure of the outside air.
  3. Baffle It makes the returning oil go the long way round. That helps it cool before the pump draws it in again.
  4. Strainer It catches only the large particles. That way it slows the oil less than a filter would.
  5. Pump It makes flow, not pressure. Pressure builds only when the flow meets resistance, such as a load on a cylinder.
  6. Electric motor The motor or engine driving the pump is called the prime mover.
  7. Pressure line It runs from the pump's outlet to the control valve.
  8. Relief valve It sends the pump's oil back to the reservoir. Then it closes again when the pressure drops.
  9. Pressure gauge Most have a curved Bourdon tube inside. It straightens as the pressure rises and moves the pointer.
  10. Filter Here it sits on the return line. That is just before the oil goes back into the reservoir. Its element has to be changed regularly.

Control and work 8

  1. Check valve Flow pushes the ball off its seat. A spring and any flow the other way push it shut.
  2. Accumulator Gas in the top is squeezed as oil is pumped in. It pushes the oil back out when the system needs it.
  3. Directional control valve Moving a lever slides a spool inside. That opens one path for the oil and closes another.
  4. Hoses Hose is used where pipe or tube cannot be. This is because it bends as the machine moves.
  5. Cylinder Oil on one side of the piston inside drives the rod out. Oil on the other side brings it back.
  6. Hydraulic motor It works like a pump run backward. The oil pushes it round and its shaft drives the machine.
  7. Return line It ends below the oil level in the reservoir. Its opening is turned away from the pump's inlet.
  8. Cooler It keeps the oil temperature within safe limits, so the oil lasts.

How this list was compiled: Every name checked on 2026-09-30, a name kept only where two of these three use it: (1) US Navy, Fluid Power, NAVEDTRA 14105 (1990), full text at https://archive.org/details/fluidpower; (2) US Army, FM 5-499 Hydraulics (1997), full text at https://archive.org/details/fm-5-499-hydraulics-1997; (3) Wikipedia, Hydraulic machinery, https://en.wikipedia.org/wiki/Hydraulic_machinery, text only. The detail lines are in our own words. Licence: own work

The drawing: Drawn for this site on 2026-09-30 from plain geometry; no maker's unit, nothing traced. Licence: own work

How it works

This simple hydraulic system diagram quiz is on one basic circuit: one pump, one control valve, one cylinder and one hydraulic motor, drawn as pictures, not symbols.

Read the full guide

Names that get swapped

The electric motor is the ribbed body on the tank lid that turns the pump; the hydraulic motor is the round one at the lower right, which the oil turns. The relief valve hangs from the pressure line with a spring inside; the check valve sits on the line and holds a ball and a spring. The strainer is the mesh can in the oil; the filter is the can on the return pipe.

  • The accumulator is the rounded bottle standing on the pressure line. The cylinder is the barrel with a rod coming out of one end.
  • Both lines run through both drawings. The pressure line is asked on the power unit, the return line where it leaves the valve block.

Questions and answers

What is an actuator in a hydraulic system?

The part that turns the oil's power into force and motion. A cylinder is a linear actuator: it pushes or pulls in a straight line. A hydraulic motor is a rotary actuator: it turns a shaft. The quiz asks for both.

What is the difference between a hydraulic pump and a hydraulic motor?

A pump takes mechanical power from an engine or electric motor and turns it into oil flow. A hydraulic motor does the reverse: the flow turns its shaft. Here the pump sits on the tank and the hydraulic motor at the end of two hoses.

What is the difference between a relief valve and a check valve?

A relief valve limits pressure: it opens only when the pressure climbs too high. A check valve sets direction: oil passes one way and is blocked the other. Here it sits ahead of the accumulator, so the stored oil cannot run back.

What are the types of hydraulic diagrams?

The US Army's hydraulics manual lists four: block, cutaway, pictorial and graphical. A pictorial shows parts in their actual shapes, a cutaway shows the insides, and a graphical one uses symbols. This quiz is pictorial, with a few parts cut open.

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