🔍 Key Concepts

• Relation between spring compression and outlet pressure setpoint in a pressure-reducing valve • How turning an adjusting screw (clockwise vs counterclockwise) changes spring compression in the direction shown in the illustration • Balance of forces between spring force and reduced outlet pressure acting on the piston/diaphragm in an internal-pilot regulator

💭 Think About

• Look at how the adjusting screw threads into the top bonnet: when you turn it clockwise, does the screw move into the spring chamber or out of it? What does that do to the spring length? • Ask yourself: to get a lower outlet pressure, do you want the spring pushing harder or softer on the internal pilot and piston assembly? • Trace the force path: adjusting screw → top spring seat → main spring → pilot/piston. If the spring force decreases, what happens to the position of the valve plug and the downstream pressure?

✅ Before You Answer

• Verify which direction of rotation (clockwise vs counterclockwise) will physically compress or relax the main adjusting spring in this specific sketch. • Confirm that more spring compression = higher downstream pressure setpoint, and less spring compression = lower setpoint. • Eliminate any options where the direction of rotation does not match the mechanical effect on spring compression you just determined from the illustration.