Koso EPB801 Electric Valve Positioner

Product Introduction

The Koso EPB801 Electric Valve Positioner is a critical accessory for pneumatic control valves, designed to precisely regulate valve position in industrial processes. It receives a 4–20 mA DC input signal from a controller and converts it into a pneumatic output to drive the valve, while mechanical feedback from the valve stem ensures accurate position tracking. The positioner sends electrical signals to the upper system for real-time monitoring, making it essential for closed-loop control systems. With a rugged aluminum alloy housing and multiple explosion-proof ratings, it suits diverse industrial environments from -20°C to 80°C.

Product Features

Precision Control & Feedback:

Input Signal: Standard 4–20 mA DC (split ranges: 4–12 mA/12–20 mA/10–50 mA for EP-15/17/25/27 models).

Mechanical Feedback: Stem displacement is converted to electrical signals for real-time system monitoring.

Versatile Actuator Compatibility:

Straight Stroke: 12–100 mm; Angular Stroke: 0–90 degrees.

Adaptable to small/large actuators via load control strategies and cam mechanism adjustments.

Pneumatic Performance:

Gas Source Pressure: 0.14–0.16 MPa or 0.17–0.50 MPa.

Gas Consumption: 5 NL/min at 0.4 MPa; low-power amplifier design reduces energy use.

Accuracy & Reliability:

Backlash: <1%; Dead Zone: <0.4% for precise valve positioning.

Output Characteristics: Linear (configurable to quick-open, percentage, etc., via cam mechanism).

Environmental & Safety Features:

Temperature Range: Flameproof: -20°C–60°C; Standard: -40°C–80°C.

Explosion-proof Types: Flameproof and ordinary models available.

IP Protection: Suitable for harsh environments with ≤90% relative humidity.

Design & Installation:

Housing: Aluminum alloy (weight: 3.5 kg).

Air Connection: ZG1/4 thread for easy pneumatic integration.

Amplifier Conversion: Easily switches between positive/negative action for single-acting actuators.

echnical parameters and performance:

Input Signal: Standard: 4-20 MADC.

Split: 4-12 MADC 12-20 MADC 10-50 MADC (ep-15.17. EP-25.27.) ...

Input impedance: 250 Euro (4-20 MADC)100 Euro (10-50 MADC).

Nominal Stroke: straight stroke: 12... 100 mm, Angle: 0-90 degrees ...

Gas source pressure: 0.14-0.16 mpa 0.17-0.50 mpa.

Gas Consumption: 5NL/min (when gas pressure is 0.4 MPa) ...

Backlash: less than 1% dead zone: less than 0.4% .

Output characteristics: linear (can be changed to fast open, such as percentage characteristics) ...

Ambient temperature: Flameproof type-20-+ 60℃ normal type-40-+ 80℃

Relative Humidity: not more than 90% ...

Explosion-proof type: flame-proof type, ordinary type. ZG1/4 air source interface ...

Case material: aluminum alloy. Weight: 3.5 kg

EPB800 series valve positioner features:

Apply to small capacity and large capacity actuator: adopt load control missile policy, select the corresponding missile policy can get suitable for the actuator positioner.

gas consumption is small: the power consumption of the amplifier is small, the capacity is large.

Output characteristics can be selected: because there is a cam mechanism in the feedback mechanism, output characteristics other than the standard ones can be selected.

4various feedback mode corresponding model: as long as the replacement of the cam device, can be used for the following corresponding actuator.

* direct travel actuator: standard-------------EPB8O1 * Angular Travel Actuator: Standard----. EPB8 02, easily converted to reaction amplifier: when a single-action actuator requires reaction control, a positive-action amplifier can easily be converted to a negative-action amplifier.