The Belimo B229+LF24-SR-S US is a 1-1/4 in. 2-way characterized control valve (CCV), Cv 10, with a stainless steel ball and stem, assembled with the Belimo LF24-SR-S US fail-safe actuator for modulating 2...10 V control on a 24 VAC/DC supply.
A TEFZEL® characterized disc gives the valve an equal percentage flow characteristic. Rated 600 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
TEFZEL® disc produces an equal percentage flow characteristic.
Fail-Safe Actuator
LF24-SR-S US is a fail-safe actuator: fail-safe direction selectable by mounting L/R; fail-safe running time <20 s @ -20...50°C, <60 s @ -30°C.
Modulating Control
Proportional control on 2...10 V, with 2...10 V position feedback.
MP-Bus Communication
Communicative control via MP-Bus (MP-Bus max. 16).
Auxiliary Switch
1x SPDT, 1 mA...3 A (0.5 A inductive), DC 5 V...AC 250 V, adjustable 0...95°.
Pressure Ratings
600 psi body pressure rating, 200 psi close-off pressure.
ZOT Supply is an authorized distributor of Belimo products.
Technical Specifications
| Valve: Belimo B229 | |
|---|---|
| Valve Size | 1.25" [32] |
| Fluid | chilled or hot water, up to 60% glycol |
| Fluid Temperature Range | 0...250°F [-18...120°C] |
| Body Pressure Rating | 600 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 | 10 |
| 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 | 20 GPM |
| Valve Weight | 1.4 lb [0.62 kg] |
| Actuator: Belimo LF24-SR-S US | |
|---|---|
| Nominal voltage | AC/DC 24 V |
| Nominal voltage frequency | 50/60 Hz |
| Nominal voltage range | AC 19.2...28.8 V / DC 21.6...35.0 V |
| Power consumption in operation | 2W |
| Power consumption in rest position | 0.8 W |
| Transformer sizing | 3.5 VA |
| Auxiliary switch | 1x SPDT, 1 mA...3 A (0.5 A inductive), DC 5 V...AC 250 V, adjustable 0...95° |
| Connection supply/control | cable 3 ft. [1 m], 4x 0.75 mm² |
| Parallel operation | Yes (note the performance data) |
| Communicative control | MP-Bus |
| Number of nodes | MP-Bus max. 16 |
| Torque motor | 35 in-lb [4 Nm] |
| Torque Fail-Safe | 4 Nm |
| Operating Range Y | 2...10 V |
| Input impedance | 100 kΩ |
| Operating range Y variable | Start point 0.5...30 V End point 2.5...32 V |
| Operating modes optional | variable (VDC, on/off, floating point) |
| Position Feedback U | 2...10 V |
| Position feedback U note | Max. 1 mA |
| Position feedback U variable | Start point 0.5...8 V End point 2.5...10 V |
| Position accuracy | ±5% |
| Direction of motion motor | selectable with switch L/R |
| Direction of motion variable | electronically reversible |
| Direction of motion fail-safe | selectable by mounting L/R |
| Manual override | No |
| Angle of rotation | Max. 95° |
| Angle of rotation note | Adjustable 37...100% with integrated mechanical limitation |
| Running Time (Motor) | 150 s / 90° |
| Running time motor variable | 75...300 s |
| Running time fail-safe | <20 s @ -20...50°C, <60 s @ -30°C |
| Sound power level, motor | 36 dB(A) |
| Adaptation Setting Range | with Belimo Assistant 2 |
| Override control | MIN (minimum position) = 0% MID (intermediate position, AC only) = 50% MAX (maximum position) = 100% |
| Override control variable | MIN = 0%...(MAX – 32%) MID = MIN...MAX MAX = (MIN + 32%)...100% |
| Mechanical interface | Universal shaft clamp 8...16 mm |
| Position indication | Mechanical |
| Service life | Min. 60'000 fail-safe positions |
| Power Source (UL) | Class 2 Supply |
| Degree of Protection (NEMA/UL) | NEMA 2 |
| Housing | UL Enclosure Type 2 |
| Agency Listing | cULus acc. To UL 873 and CAN/CSA C22.2 No. 24-93 |
| 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 |
| Actuator Weight | 3.2 lb [1.5 kg] |
Documentation
Belimo B229+LF24-SR-S US Technical Data Sheet (Valve + Actuator)LF Actuator on CCV / PICCV / HTCCV Installation InstructionsCCV Installation InstructionsCharacterized Control Valve (CCV) Technical DocumentationCCV Accessories DocumentationElectronic Valve Applications GuideBelimo 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 B229+LF24-SR-S US?
The B229 valve is rated Cv 10. At a 4 psi pressure drop it passes 20 GPM of water.
What size and pipe connection does the B229+LF24-SR-S US use?
1-1/4 in. (1.25" [32]) with internal thread NPT (female) connections.
Is the B229+LF24-SR-S US fail-safe?
Yes. The LF24-SR-S US is a fail-safe actuator. Fail-safe running time: <20 s @ -20...50°C, <60 s @ -30°C.
What control signal does the B229+LF24-SR-S US accept?
The LF24-SR-S US accepts modulating 2...10 V control, operating range Y 2...10 V, and communicative control via MP-Bus.
What power supply does the B229+LF24-SR-S US need?
Nominal voltage AC/DC 24 V. Transformer sizing: 3.5 VA.
What warranty does the B229+LF24-SR-S US have?
A Belimo 5-year warranty on all components from the date of production, with the first two years unconditional.
What is the close-off pressure of the B229+LF24-SR-S US?
200 psi close-off pressure, with a 600 psi body pressure rating.
What fluids can the B229+LF24-SR-S US control?
Chilled or hot water, up to 60% glycol, fluid temperature range 0...250°F [-18...120°C].
Specifications per Belimo B229 technical data sheet (2026-02-07) and Belimo LF24-SR-S US technical data sheet (2026-02-13); 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:
- 1-1/4 Inch
- CV Rating:
- 10
- GPM:
- 20 @ 4 psi
- Material:
- Stainless Steel
- Actuator Type:
- Fail-Safe
- Voltage:
- 24VAC/DC
- Control Signal:
- 2-10VDC
- Auxillary Switch:
- Yes
- Enclosure:
- NEMA 2
