🔍 Key Concepts

• Identify what type of valve/device is shown on the right-hand side of the illustration (think of an engine starting or control valve). • Determine which component supplies a mechanical closing force when no operating pressure is applied (typically a spring). • Trace the moving spindle/stem of the device and see which labeled part actually pushes it shut when the actuating pressure is released.

💭 Think About

• Follow the valve spindle on the right-hand device from the seat at the bottom up to the actuating area; which labeled part is clearly storing energy to push it closed? • Ask yourself: if air/oil pressure to this device suddenly disappeared, which component would still act to move the valve to the closed position? • Look carefully at which labels point to a coil spring versus which point to passages, pistons, or guides.

✅ Before You Answer

• Be sure you are focusing on the right-hand vertical assembly, not the main valve on the left. • Confirm which label clearly identifies the main closing spring acting on the valve stem, not a pilot piston or housing. • Verify that the part you choose would still provide closing force without any external pressure, relying only on stored mechanical energy.