Reliability at Highest Operating Pressures

Spherical valves are used as safety and shut-off equipment for turbines and pumps with 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 forged or welded constructions using high quality steels. They generally have two sealing systems: A maintenance seal that facilitates inspections and outage work without having to dewater the pipeline as well as a main operating seal that can also be used for priming the turbine spiral case.

Closing and opening of the spherical valve is done via weight, water or oil hydraulics. The water for actuating the seal rings is sourced from the penstock and fed to the hydraulic control system via suitable filters. The hydraulic servomotor 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 water hammer. The control system is designed such that it is not possible to actuate the spherical valves in case the seal rings are under pressure or only partially in position. Locking mechanism additionally render it impossible for the valve rotor to move while performing maintenance work.