Belimo EP250+AKRX-E N4 : Pressure Independent Valve (EPIV4), 2-Way Flanged, 2 1/2" [DN65], 132 GPM, Fast Electronic Fail-Safe, 24VAC/DC, Modulating or Communicative, BACnet MS/TP, Modbus RTU, MP-Bus, ANSI 125, NEMA 4

The Belimo EP250+AKRX-E N4 is a 4th-generation flanged Electronic Pressure Independent Valve (EPIV4) pairing a 2 1/2″ [DN65] characterized control valve with an ultrasonic flow meter and a fast electronic fail-safe actuator in one assembly. Rated for a nominal flow of 132 GPM with an ANSI Class 125 flat-face body, the EP250+AKRX-E N4 delivers true volumetric flow control independent of system pressure fluctuations, with 0% leakage when closed.

What sets the EP250+AKRX-E N4 apart is Belimo's ultrasonic flow measurement with built-in glycol and temperature compensation: the EP250+AKRX-E N4 reports true flow, accumulated total volume, fluid temperature, and glycol percentage directly to your building automation system. The actuator The actuator drives to its selected fail-safe position in <35 s on power loss using stored capacitor energy. It is configured wirelessly over NFC with the free Belimo Assistant 2 app for fast commissioning and downloadable calibration reports.

Key Features

Technical Specifications

Documentation

• EP250+AKRX-E N4 Technical Datasheet
• BACnet Interface Description (EPIV 2-Way V4)
• Modbus Register (EPIV 2-Way V4)
• Data Pool Values (EPIV 2-Way V4)

Frequently Asked Questions

The EP250+AKRX-E N4 holds the flow you set regardless of pressure changes elsewhere in the loop. Its built-in ultrasonic flow meter measures actual flow and the actuator continuously adjusts the valve to maintain setpoint, so balancing is automatic and coils never over- or under-flow.

Compared with earlier EPIV models, the EP250+AKRX-E N4 adds ultrasonic flow measurement with glycol compensation, true total-volume and glycol-percentage outputs, an integrated fluid-temperature sensor, higher flow capacity, extended BACnet MS/TP, Modbus RTU, MP-Bus and analog communication, and built-in NFC for setup with Belimo Assistant 2.

Natively BACnet MS/TP, Modbus RTU, and Belimo MP-Bus, plus a 2–10 V analog input (4–20 mA with the ZG-R01 resistor). Hybrid operation lets you combine a digital setpoint with analog override.

Yes. The ultrasonic sensor compensates for glycol concentration and reports the glycol percentage, while an integrated Pt1000 sensor measures fluid temperature — useful for energy/BTU monitoring and verifying your glycol mixture.

The EP250+AKRX-E N4 is an electronic fail-safe actuator. Stored capacitor energy drives the valve to an adjustable fail-safe position (FC/FO or 0–100% set on the POP rotary knob) within <35 s — there are no mechanical springs to fatigue.

Yes. ZOT Supply is an authorized Belimo distributor, so the EP250+AKRX-E N4 carries Belimo's full 5-year warranty and ships factory-tested, typically within 1–3 business days.