The Belimo B254+AFRX24-MFT-S is a 2 in. 2-way characterized control valve (CCV), Cv 240, with a stainless steel ball and stem, assembled with the Belimo AFRX24-MFT-S spring-return fail-safe actuator for MFT programmable control on a 24 VAC/DC supply.
A no Disc (full flow) characterized disc gives the valve an equal percentage flow characteristic. Rated 400 psi body pressure and 200 psi close-off, for chilled or hot water, up to 60% glycol from 0...250°F [-18...120°C].
Best For
- Heating and cooling coils in air handling units
- Fan coil unit heating and cooling coils
- Unit ventilators
- VAV box reheat coils
- Bypass loops
- Hydronic systems with variable flow
Warranty
This Belimo characterized control valve product carries a 5-year warranty on all components from the date of production, with the first two years unconditional.
Key Features
Characterized Disc
No Disc (full flow) disc produces an equal percentage flow characteristic.
Spring-Return Fail-Safe
AFRX24-MFT-S is a spring-return fail-safe actuator: fail-safe direction reversible with cw/ccw mounting; fail-safe running time <20 s @ 68°F [20°C].
MFT Programmable
Operating range Y 2...10 V; optional modes variable (VDC, PWM, on/off, floating point).
Auxiliary Switch
2x SPDT, 1 mA...3 A (0.5 A inductive), DC 5 V...AC 250 V, 1x 10% / 1x 11...90%.
Pressure Ratings
400 psi body pressure rating, 200 psi close-off pressure.
Ball and Stem
Stainless steel ball, stainless steel stem, PTFE seat.
ZOT Supply is an authorized distributor of Belimo products.
Technical Specifications
| Valve: Belimo B254 | |
|---|---|
| Valve Size | 2" [50] |
| Fluid | chilled or hot water, up to 60% glycol |
| Fluid Temperature Range | 0...250°F [-18...120°C] |
| Body Pressure Rating | 400 psi |
| Close-Off Pressure (∆ps) | 200 psi |
| Flow Characteristic | equal percentage |
| Leakage Rate | 0% for A–AB |
| Pipe Connection | Internal thread NPT (female) |
| Servicing | maintenance-free |
| Flow Pattern | 2-way |
| Controllable Flow Range | 75° |
| Cv | 240 |
| Characterized Disc | None |
| Valve Body | Nickel-plated brass body |
| Stem | stainless steel |
| Stem Seal | EPDM (lubricated) |
| Seat | PTFE |
| Characterized Disc | No Disc (full flow) |
| O-ring | EPDM (lubricated) |
| Ball | stainless steel |
| Flow Rate @ 4 psi Pressure Drop | 480 GPM |
| Valve Weight | 5.3 lb [2.4 kg] |
| Actuator: Belimo AFRX24-MFT-S | |
|---|---|
| Nominal voltage | AC/DC 24 V |
| Nominal voltage frequency | 50/60 Hz |
| Nominal voltage range | AC 19.2...28.8 V / DC 21.6...28.8 V |
| Power consumption in operation | 7.5 W |
| Power consumption in rest position | 3W |
| Transformer sizing | 10 VA |
| Auxiliary switch | 2x SPDT, 1 mA...3 A (0.5 A inductive), DC 5 V...AC 250 V, 1x 10% / 1x 11...90% |
| Switching capacity auxiliary switch | 1 mA...3 A (0.5 A inductive), DC 5 V...AC 250 V |
| Overload Protection | electronic throughout 0...95° rotation |
| Operating Range Y | 2...10 V |
| Operating range Y note | 4...20 mA w/ ZG-R01 (500 Ω, 1/4 W resistor) |
| Input impedance | 100 kΩ for 2...10 V (0.1 mA), 500 Ω for 4...20 mA, 1500 Ω for PWM, On/Off and Floating point |
| Operating range Y variable | Start point 0.5...30 V End point 2.5...32 V |
| Operating modes optional | variable (VDC, PWM, on/off, floating point) |
| Position Feedback U | 2...10 V |
| Position feedback U note | Max. 0.5 mA |
| Position feedback U variable | VDC variable |
| Direction of motion motor | selectable with switch |
| Direction of motion fail-safe | reversible with cw/ccw mounting |
| Manual override | 5 mm hex crank (3/16" Allen), supplied |
| Angle of rotation | 90° |
| Running Time (Motor) | 150 s / 90° |
| Running time motor variable | 70...220 s |
| Running time fail-safe | <20 s @ 68°F [20°C] |
| Sound power level motor | 45 dB(A) |
| Sound power level, fail-safe | 62 dB(A) |
| Adaptation Setting Range | off (default) |
| Override control | MIN (minimum position) = 0% MID (intermediate position) = 50% MAX (maximum position) = 100% |
| Position indication | Mechanical |
| Power Source (UL) | Class 2 Supply |
| Degree of Protection (NEMA/UL) | NEMA 2 |
| Housing | UL Enclosure Type 2 |
| Agency Listing | cULus acc. to UL60730-1A/-2-14, CAN/CSA E60730-1:02 CE acc. to 2014/30/EU and 2014/35/EU |
| Quality Standard | ISO 9001 |
| UL 2043 Compliant | Suitable for use in air plenums per Section 300.22(C) of the NEC and Section 602 of the IMC |
| Ambient humidity | Max. 95% RH, non-condensing |
| Ambient temperature | -22...122°F [-30...50°C] |
| Storage temperature | -40...176°F [-40...80°C] |
| Servicing | maintenance-free |
| Housing material | Galvanized steel and plastic housing |
| Actuator Weight | 5.4 lb [2.4 kg] |
Compatible Accessories
Belimo accessories for the B254+AFRX24-MFT-S, available from ZOT Supply.
Valve Accessories
Gateways
Documentation
Belimo B254+AFRX24-MFT-S Technical Data Sheet (Valve + Actuator)CCV 4-Pin Removal Installation InstructionsCCV Installation InstructionsCharacterized Control Valve (CCV) Technical DocumentationCCV Accessories DocumentationElectronic Valve Applications GuideZTH BrochureMP-Bus Technology: Notes for Project PlanningBelimo Ball Valve Master FormatSuccess Story: Habitat for Humanity Home with Belimo CCVSuccess Story: New York PostSuccess Story: Sonoma State University RenovationSuccess Story: Western Wyoming Community CollegeFrequently Asked Questions
What is the Cv of the Belimo B254+AFRX24-MFT-S?
The B254 valve is rated Cv 240. At a 4 psi pressure drop it passes 480 GPM of water.
What size and pipe connection does the B254+AFRX24-MFT-S use?
2 in. (2" [50]) with internal thread NPT (female) connections.
Is the B254+AFRX24-MFT-S fail-safe?
Yes. The AFRX24-MFT-S is a spring-return fail-safe actuator. Fail-safe running time: <20 s @ 68°F [20°C].
What control signal does the B254+AFRX24-MFT-S accept?
The AFRX24-MFT-S accepts MFT programmable control, operating range Y 2...10 V (4...20 mA w/ ZG-R01 (500 Ω, 1/4 W resistor)).
What power supply does the B254+AFRX24-MFT-S need?
Nominal voltage AC/DC 24 V. Transformer sizing: 10 VA.
What warranty does the B254+AFRX24-MFT-S have?
A Belimo 5-year warranty on all components from the date of production, with the first two years unconditional.
What accessories are available for the B254+AFRX24-MFT-S?
ZOT Supply carries these compatible Belimo accessories: ZS-CCV-110 (Weather shield for B2, B3 CCV, with AFRB(X)); UK24BAC (Gateway MP to BACnet MS/TP); UK24MOD (Gateway MP to Modbus RTU); UK24LON (Gateway MP to LonWorks).
What is the close-off pressure of the B254+AFRX24-MFT-S?
200 psi close-off pressure, with a 400 psi body pressure rating.
What fluids can the B254+AFRX24-MFT-S control?
Chilled or hot water, up to 60% glycol, fluid temperature range 0...250°F [-18...120°C].
Specifications per Belimo B254 technical data sheet (2026-02-07) and Belimo AFRX24-MFT-S technical data sheet (2026-08-18); flow rate per Belimo CCV Technical Documentation (P10419 - 09/13); warranty per Belimo CCV Master Format, Section 230923.11. Content updated November 2026.
- Valve Pattern:
- 2-Way
- Valve Size:
- 2 Inch
- CV Rating:
- 240
- GPM:
- 480 @ 4 psi
- Material:
- Stainless Steel
- Actuator Type:
- Fail-Safe
- Voltage:
- 24VAC/DC
- Control Signal:
- MFT Programmable
- Auxillary Switch:
- Yes
- Enclosure:
- NEMA 2
