Application

Electropneumatic linear actuators for attachment to Type 3214

and Type 3260 Valves as well as Series V2001 Valves

Rated travel   15 and 30 mm

Actuator area  120 and 350 cm²

 

 

The Type 3372 Electropneumatic Actuator is available in the following versions:

•• Version with integrated i/p converter, 120 cm² actuator area and 15 mm rated travel (Fig. 1)

•• Version with Type 3725 Positioner (direct attachment), 120 cm² actuator area and 15 mm rated travel (Fig. 2)

•• Version with Type 3725 Positioner (direct attachment), 350 cm² actuator area and 15 or 30 mm rated travel(Fig. 3)

The actuators are suitable for attachment to Series V2001 Valves (e.g. Type 3321, Type 3323, Type 3531, Type 3535) as well as Type 3214 and Type 3260 Valves. The actuators mainly consist of two diaphragm cases, a rolling diaphragm and internal springs. The Type 3372 Electropneumatic Actuator is controlled by a 4 to 20 mA signal. For throttling service, an i/p converter is integrated into the actuator or a Type 3725 Positioner is mounted to the rod-type yoke using a support element.

 

-- Permissible operating temperatures from -35 to +90 °C

Only when a positioner is mounted

-- Mechanically adjustable limit stop · Only when a positioned is mounted and for 120 cm² actuators

-- Handwheel · Only when a positioner is mounted and for 120 cm² actuators

-- Explosion protection for a mounted Type 3725 Positioner

II 2G Ex ia IIC T4 according to ATEX, intrinsically safe Ex ia IIC T4 according to CSA Group, 1Ex ia IIC T4 Gb X according to GOST

-- Type 4744‑2 Limit Switch (Fig. 4) · With explosion protection II 2G Ex db IIC T6-T5 and degree of protection IP 66

A clamping plate can be used to mount it · See Data Sheet T 8367

 

The electric control signal issued by the controller as a reference variable from 4 to 20 mA is transmitted to the i/p converter where it is converted into a proportional pressure signal.

The pressure signal creates a force that acts on the measuring diaphragm. This force is then compared with the force of the range spring. The movement of the measuring diaphragm is transmitted by the lever to the force switch, and finally a corresponding signal pressure is produced.

A change in input signal causes the actuator stem to move to the position determined by the reference variable. The flow rate through the valve changes accordingly.

Principle of operation (actuator with mounted positioner)

Details on principle of operation are described in the Data Sheet T 8394 for Type 3725 Positioner.