As the valve stem moves, a feedback linkage (connected to the actuator stem) adjusts the positioner's internal feedback spring. This movement counterbalances the force exerted by the bellows, bringing the system back into equilibrium once the target position is reached. 3. Installation and Mounting Guidelines
Minimum: 3 psi (0.2 bar) above maximum required actuator pressure.
Before attempting calibration, ensure you have a clean air supply, a regulated pneumatic calibration signal source, and accurate pressure gauges. Step 1: Pre-Check and Safety Isolate the control valve from the live process.
Engineered for rotary actuators. It uses a cam-operated feedback system to translate rotary motion into the force-balance mechanism. Fisher 3560 Valve Positioner Manual Pdf
and 3661 for improved diagnostic capabilities and vibration resistance. Key Functions & Benefits The primary role of the
The remains a reliable component for critical control applications. Having access to the manual ensures that installation, calibration, and maintenance are performed correctly, preventing downtime.
Connect the air supply to the "Supply" port (typically 10% above max actuator requirement). As the valve stem moves, a feedback linkage
With the 3 psi (input) applied, adjust the zero nut until the valve just starts to move off its seat.
Designed to accommodate a wide variety of sliding-stem and rotary-shaft valves, the 3560 series excels in both throttling and on-off applications.
Adjust the until the valve stem just begins to move from its resting position or hits its baseline seat. Set the Span: Installation and Mounting Guidelines Minimum: 3 psi (0
Observe the valve travel. If the valve does not reach the 100% mark, or hits the mechanical stop prematurely, adjust the Span Adjustment Nut .
Align the feedback arm so it sits perpendicular to the valve stem at 50% stroke. 3. Pneumatic Connections
The Fisher 3560 series consists of top-mounted, rugged positioners primarily designed for use with pneumatic actuators, such as the Fisher 585C or 657 series. They compare the input signal from a control instrument with the valve stem position, providing corrected output pressure to the actuator until the target position is reached. Model Variations
⚠️ : Only trained personnel should attempt repair. Depressurise the system and disconnect all operating lines before performing maintenance to prevent sudden valve movement.
Repeat zero and span adjustments until the valve hits 0% and 100% at the correct input pressures. Troubleshooting