Fisher 3570 pneumatic valve positioners are used with control valve assemblies to provide an accurate valve stem position that is proportional to the input signal received from a control device. These positioners are normally used with pneumatic piston actuators. However, product types within the 3570 family can be used with pneumatic, long-stroke, cylinder, or pneumatic diaphragm actuators.
- Actuator with or without positioners and snubbers is available in an assortment of sizes, stroking speeds, thrusts, and travels to handle most control requirements.
- Yokeless construction permits a low-profile assembly by allowing close coupling to the control device; either through a bracket or, with some versions, by direct mounting on a bonnet flange.
- The cylinder (and 3570 positioner if used) can operate with supply pressures as low as 2.4 bar (35 psig) or as high as 10.3 bar (150 psig).
- Actuators have maximum rated travels of up to 206 mm (8.125 inches).
- Positioner/actuator action is easily reversed in the field with no additional parts. Positioner sensitivity, travel span, and travel starting point are factory set and need to be reset only if operating conditions have changed or if the positioner has been reversed.