Which device works off head pressure from the clarifiers?

• A. Check Valves
• B. Globe Valves
• C. Telescoping Valves
• D. Gate Valves

Answer: (C)

The main idea is that some valves are designed to use the hydrostatic head from a clarifier as their power source. A telescoping valve is built to respond directly to that head pressure: as the water level (and thus the pressure) in the clarifier changes, the valve’s piston or telescoping sleeve moves, adjusting the opening to regulate flow automatically. This lets discharge from the clarifier be throttled or limited without needing external power or signals, helping to control surges and maintain downstream conditions.

Check valves mainly rely on forward flow to stay open and close to prevent backflow; they don’t actively regulate flow based on clarifier head. Globe valves and gate valves are typically manually or externally actuated throttling or shut-off devices and don’t automatically respond to the clarifier’s head pressure.