The Belimo B277+AFRX24-MFT is a 3 in. 2-way characterized control valve (CCV), Cv 70, with a stainless steel ball and stem, assembled with the Belimo AFRX24-MFT spring-return fail-safe actuator for MFT programmable control on a 24 VAC/DC supply.
A TEFZEL® characterized disc gives the valve an equal percentage flow characteristic. Rated 400 psi body pressure and 100 psi close-off, for chilled or hot water, up to 60% glycol from 0...212°F [-18...100°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
TEFZEL® disc produces an equal percentage flow characteristic.
Spring-Return Fail-Safe
AFRX24-MFT 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).
Pressure Ratings
400 psi body pressure rating, 100 psi close-off pressure.
Ball and Stem
Stainless steel ball, stainless steel stem, PTFE seat.
Plenum Rated
UL 2043: Suitable for use in air plenums per Section 300.22(C) of the NEC and Section 602 of the IMC.
ZOT Supply is an authorized distributor of Belimo products.
Technical Specifications
| Valve: Belimo B277 | |
|---|---|
| Valve Size | 3" [80] |
| Fluid | chilled or hot water, up to 60% glycol |
| Fluid Temperature Range | 0...212°F [-18...100°C] |
| Body Pressure Rating | 400 psi |
| Close-Off Pressure (∆ps) | 100 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 | 70 |
| Valve Body | Nickel-plated brass body |
| Stem | stainless steel |
| Stem Seal | EPDM (lubricated) |
| Seat | PTFE |
| Characterized Disc | TEFZEL® |
| O-ring | EPDM (lubricated) |
| Ball | stainless steel |
| Flow Rate @ 4 psi Pressure Drop | 140 GPM |
| Valve Weight | 9.0 lb [4.1 kg] |
| Actuator: Belimo AFRX24-MFT | |
|---|---|
| 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 |
| 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) |
| 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 | 4.8 lb [2.2 kg] |
Compatible Accessories
Belimo accessories for the B277+AFRX24-MFT, available from ZOT Supply.
Valve Accessories
Gateways
Documentation
Belimo B277+AFRX24-MFT 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 B277+AFRX24-MFT?
The B277 valve is rated Cv 70. At a 4 psi pressure drop it passes 140 GPM of water.
What size and pipe connection does the B277+AFRX24-MFT use?
3 in. (3" [80]) with internal thread NPT (female) connections.
Is the B277+AFRX24-MFT fail-safe?
Yes. The AFRX24-MFT is a spring-return fail-safe actuator. Fail-safe running time: <20 s @ 68°F [20°C].
What control signal does the B277+AFRX24-MFT accept?
The AFRX24-MFT 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 B277+AFRX24-MFT need?
Nominal voltage AC/DC 24 V. Transformer sizing: 10 VA.
What warranty does the B277+AFRX24-MFT 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 B277+AFRX24-MFT?
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 B277+AFRX24-MFT?
100 psi close-off pressure, with a 400 psi body pressure rating.
What fluids can the B277+AFRX24-MFT control?
Chilled or hot water, up to 60% glycol, fluid temperature range 0...212°F [-18...100°C].
Specifications per Belimo B277 technical data sheet (2026-02-07) and Belimo AFRX24-MFT 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:
- 3 Inch
- CV Rating:
- 70
- GPM:
- 140 @ 4 psi
- Material:
- Stainless Steel
- Actuator Type:
- Fail-Safe
- Voltage:
- 24VAC/DC
- Control Signal:
- MFT Programmable
- Auxillary Switch:
- None
- Enclosure:
- NEMA 2
