Hydraulic Counterweight Butterfly Valves

Hydraulic Counterweight Butterfly Valves (also termed Pump Check or Turbine Inlet Isolation Valves) are heavy-duty safety valves designed to protect water transmission pumping stations and hydroelectric turbines against catastrophic backflow and destructive hydraulic water hammer. The valve is driven open hydraulically by high-pressure oil cylinders, while an engineered heavy lever-counterweight is simultaneously raised and mechanically latched.

Upon pump trip or emergency shutdown, the latch releases automatically, and the counterweight drives the valve closed using purely gravitational potential energy, completely independent of electric power. Zeron Fastners incorporates dual-speed progressive closing dampers (fast 70% closure followed by controlled slow 30% cushioning) to dissipate surge pressure and prevent reverse pump rotation.