🔍 Key Concepts

• How hydraulic directional control valve symbols show the number of positions (look for labels like Pos.1, Pos.2, Pos.3 and the stacked boxes). • How spring return vs detent is indicated on hydraulic schematics (spring symbol vs ball-and-notch symbol at the ends of the valve). • How to tell open-centered vs closed-centered valves from the center box of the symbol (are the flow paths connected to tank or blocked in neutral?).

💭 Think About

• On the illustration, examine the three valve symbols at the bottom (items 8, 9, and 10). What features on each end of the valve symbol tell you whether it is spring loaded or detented? • Look closely at the center position (Pos.2) of each valve: in this neutral position, are the pressure, tank, and working ports connected together or isolated from one another? • How many discrete operating positions can you see for each valve, based on the symbol boxes and position labels, and how does that narrow down the first part of each answer choice?

✅ Before You Answer

• Verify how many boxes/positions are drawn for each valve body (two-position vs three-position). • Check the end symbols: springs are usually drawn as zig‑zag/triangular shapes; detents are often shown as a small ball against a notch or similar symbol. • In the center box (Pos.2), trace the lines between P, T, and A/B ports: if all ports are blocked it is closed centered; if P is connected to T and/or A/B are open to tank, it is open centered.