Pneumatic Actuators Type 2780-1 Type 2780-2 Application Versatile actuators for use in heating, ventilation and airconditioning systems as well as for mechanical engineering. Actuator area: 120 cm² Rated travel: The Type 2780 Pneumatic Actuators are diaphragm actuators with internal compression springs. They are suitable for mounting on SAMSON Type 3213 and Type 3222 Globe Valves as well as Type 3226 and Type 3260 Three-way Valves. The actuators have the following special features: •• Diaphragm cases made of die-cast aluminum •• Easily reversible direction of action •• Integral positioner attachment (Type 2780-2) As a result, no external piping is required, regardless of the actuator's direction of action and the positioner. Versions –– Type 2780-1 (Fig. 1) · Pneumatic actuator –– Type 2780-2 (Fig. 2) · Pneumatic actuator for direct attachment of a positioner Ordering text Type 2780-1/-2 Actuator Fail-safe action: Actuator stem extends or retracts 6, 12 or 15 mm rated travel Signal pressure range … bar Signal pressure connection 1/8 NPT/G 1/8

Principle of operation The pneumatic actuator is operated by the forces acting on the diaphragm. The actuator spring force acts from the one side and the force of the signal pressure F = pst x A on the other side. If the signal pressure changes causing the force on the diaphragm to change as well, the actuator stem moves. The actuator's direction of action depends on how the springs are arranged in the actuator. Depending on which fail-safe action is to be used for the valve when the air supply fails, the springs in the actuator are installed either in the top or in the bottom diaphragm chamber...