FISHER 2625 VOLUME BOOSTER

Professional Product Specification

The Emerson Fisher 2625 Volume Booster is a pneumatic accessory designed to improve actuator stroking speed and dynamic response in control valve applications. Installed together with a valve positioner, the 2625 Series delivers high-volume air flow to valve actuators during rapid signal changes while maintaining accurate steady-state positioning performance.

The Fisher 2625, 2625SST, and 2625NS models are widely used in throttling control valves, emergency shutdown systems, and industrial automation applications requiring fast actuator response and stable pneumatic control.

General Specifications

The 2625 Series incorporates soft-seat construction and an integral bypass restriction to improve system stability and prevent positioner saturation problems.

Key Features

• Fast actuator stroking response

• High pneumatic flow capacity

• Adjustable integral bypass restriction

• Maintains steady-state valve accuracy

• Soft-seat design for reduced air consumption

• Fixed deadband design for stable operation

• Suitable for throttling or on/off service

• SIL 3 capable certification available

• Optional stainless steel construction

• Designed for severe industrial environments

The booster delivers high-volume output during rapid signal changes while still allowing smooth control during small positioner adjustments.

Typical Applications

• Pneumatic control valve systems

• Emergency shutdown valves (ESD)

• High-speed actuator applications

• Process control systems

• Oil & gas production facilities

• Petrochemical plants

• Refinery automation systems

• Power generation plants

• Industrial process automation

Operating Principle

The Fisher 2625 Volume Booster receives a pneumatic input signal from a valve positioner and amplifies the air delivery volume to the actuator. During rapid signal changes, the booster quickly supplies or exhausts air to increase actuator stroking speed. For small control adjustments, the integral bypass restriction maintains stable and accurate valve positioning without sacrificing control precision.

Advantages

• Improves control valve response time

• Enhances actuator speed without oversized positioners

• Reduces positioner saturation issues

• Provides stable and accurate valve control

• Compact and rugged construction

• Easy installation and maintenance

• Suitable for severe industrial environments

• Long operational service life

Available Models

The 2625NS version includes EPDM elastomers and high-temperature materials designed for nuclear and high-radiation environments.