Schroeder Valves - SDV series

SDV pressure maintenance device
Product photo 1 Product photo 2



The Schroeder pressure maintenance device does not allow the static pressure in the upstream pipe to fall below a defined minimum value. It does this independently of the flow volume. This means that the specified minimum pressure is maintained, from the nominal flow rate to the smallest volume. Normally pressure maintenance devices are used to avoid cavitation and partial evaporation in the pumping medium. By increasing the pressure level in the system component to be protected, they stop local steam pressure from falling below requirements. The SDV has an integrated return function, i.e. the system is also protected against reverse flow if needed.

Active principle
The active principle of the SDV is based on a spring-loaded locking cone. The cone and spring are coordinated in such a way that once the specified holding pressure has been reached, the pressure force is sufficient to lift the cone out of its seat, thus permitting flow. Unlike conventional pressure maintenance devices / counter-pressure regulators, the cone of the Schroeder pressure maintenance device has been equipped with a control profile. This allows the throttle surface at the cone seat accurately to adapt to the relevant flow rate, thus minimising the unfortunate tendency of spring-loaded locking devices to produce knocking or hammering noises at low flow rates. The SDV is therefore suitable for systems with a wide operating range and frequent partial load operation.