• Turbine Main Inlet Valve
  • Pump Main Inlet Valve

Key Features

The HYDRO-BALL valve type “HBP” is a centred ball valve proposed with an upstream maintenance movable seat and a downstream service movable seat, controlled with water or oil.

  • Design pressure: PN40, PN50, PN68, PN100, PN120 and more
  • Bore diameter: DN300 to DN2000
  • Compact valve with integrated flanges or flanged valve
  • Hydraulic actuator with counterweight (for closing)
  • Design dedicated to hydropower plant turbine protection
  • Results of several experienced technologies in hydro environment

Design Benefits

Heavy Duty Design

  • Exclusively built in forged steel and casted steel for the large size body
  • Forged steel ball with bolted martensitic stainless steel seats and bolted martensitic stainless steel trunnions
  • Bearings supports directly on the body
  • Bearing “out of water” with accessible trunnions seals from exterior
  • Bronze built high resistance bearings with graphite or PTFE inserts (possibility for bronze lubricated bearing)


  • Positive safety: valve closing themselves in absence of energy
  • Piloted manual maintenance upstream movable seat
  • Piloted automatic service downstream movable seat
  • Long term in-line tightness with piloted set-up piston effect seat and metal/metal tightness
  • Metal/metal sealing nature adapted to the water quality
  • Possibility to lock mechanically the upstream maintenance seat to secure an m aintenance operation on the downstream one with penstock under water
  • Interlock systems to avoid any mistake during operation of the ball valve:
    • 1 mechanic on the actuator → Authorize the closing of the downstream movable seat on the ball when the actuator arm is in closed position (valve completely closed)
    • 1 hydraulic on the actuator → Authorizes the closing of the downstream movable seat on the ball when the hydraulic pressure inside the actuator is zero (valve completely closed)
    • 1 mechanic on the downstream seat → Authorizes the opening of the ball only when the downstream seat is in open position


  • Minimized head loss as internal bore is strictly in accordance with the bore diameter of the penstock connections
  • Minimal valve overall dimensions
  • Very easy valve disassembling with connection spacers
  • Tightness components dismountable and easily replaceable by the downstream side of the valve


  • Optimized hydraulic actuator with counterweight
  • Do not require a pit for the counterweight
  • Standard range dedicated to this application
  • Complete compact system


  • 3rd inductive limit switch on the hydraulic actuator for a partial closing
  • Sliding pads under valve feet
  • Vent valve
  • Drain pipe and valve
  • Locking device for the upstream maintenance seat
  • Locking device for the hydraulic actuator
  • Mechanical limit switches
  • Dismantling flange
  • Integral connection flanges
  • Other connecting ends dimensions
  • Metal/Metal tightness tungsten carbide/tungsten carbide
  • Metal/Metal tightness stellite/stellite
  • Bypass (internal or external)