Spherical valves

Reliability at highest operating pressure

Spherical valves are used as safety and shut-off equipment for turbines and pumps in conditions under high operating pressure. They close automatically without outside energy and in emergency cases even against unidirectional pressure at maximum flow rate. ADAMS spherical valves are welded constructions or forged using high quality steels. They generally have two sealing systems. In first place the inspection seal ring that facilitates maintenance work without having to empty the pressure line. In the second place the operating seal ring – taking the place of a bypass – which is also used for filling the turbine housing.

Closing and opening of the spherical valve is done via weight, feed water or oil hydraulics. The feed water for actuating the gaskets is sourced from the penstock and fed to the hydraulic control system via suitable filters. The hydraulic servo drive as well as the counterweight are flanged directly onto the valve body and do not require any additional anchoring. End position dampening equipment facilitates optimum closing characteristics to prevent from water hammering. The control system is designed such that it is not possible to actuate the spherical valves in case the gaskets are under pressure or only partially in position. Sealable latching bolts additionally render it impossible for the sphere to move while performing maintenance work.


  • High operating pressures
  • Recommended as safety valves
  • Close automatically
  • Two sealing systems


Hydropower brochure