Siemens SFP11U ZONE VALVE ELECTRONIC ACTUATOR, 120 VAC, 2-POSITION, NO, SR.Siemens SFP11U Zone Valve Electronic Actuator, 120 Vac, 2 Position, NO, SR. SF Series electronic zone valve actuator, 120 Vac, normally open, 2 position, with spring return. Works with Siemens 599 Series zone valves with 1 10 inch (2. 5 mm) stroke. UL listed for plenum installations, manual override. Additional Information Actuator TypeElectronic Control or Fire Smoke TypeControl Damper Force105 N Fail SafeYes Control Signal2 position Positioning