Siemens 331-2904 Damper Actuator, Pneumatic, Number 4, 4" Stroke, 3 to 7 psi, Integral Pivot Mounting, UL Recognized for Fire/Smoke Applications

Siemens 331-2904 Damper Actuator, Pneumatic, Number 4, 4" Stroke, 3 to 7 psi, Integral Pivot Mounting, UL Recognized for Fire/Smoke Applications. Siemens Nos. 3, 4 and 6 Pneumatic Damper Actuators are heavy-duty, spring return actuators designed to drive large dampers and other applications requiring large diaphragm area and long stroke.