Double Seated Valves with a pressure balanced plug are used in case of high allowable pressure drops and low requirements to trim impermeability. Separate top and bottom guides provide heavy duty plug and stem support throughout the valve stroke range. Low pressure recovery combined with considerably high capacity allows, in some cases, efficiently using the valve as anti-cavitation type. By means of the seats change-over, it is possible to change the valve NO-NC functions using one and the same reciprocating actuator.