Description
The Belimo B338+AFRB24-SR is a 1.5-inch, 3-way characterized control valve assembly with a factory-fitted 24 V spring return modulating actuator. It provides accurate mixing or diverting flow control with a Cv of 19 for hydronic HVAC applications requiring dependable fail-safe operation.
Technical Specifications
| Condition |
New/Never Used Surplus |
| Brand |
Belimo |
| Category |
Control Valves |
| Part Number |
B338+AFRB24-SR |
| Subcategory |
Characterized Control Valves |
| Valve Type |
Characterized Control Valve (CCV) |
| Valve Size |
1.5 in (DN 40) |
| Flow Pattern |
3-way mixing / diverting |
| Cv Rating |
19 |
| Flow Characteristic |
A-port equal percentage, B-port modified |
| Leakage Rate |
0% A–AB, <2% B–AB |
| Body Pressure Rating |
400 psi |
| Close-Off Pressure |
200 psi |
| Pipe Connection |
Female NPT threaded |
| Fluid Compatibility |
Chilled or hot water, up to 60% glycol |
| Fluid Temperature Range |
0…250°F (-18…120°C) |
| Valve Body Material |
Nickel-plated brass |
| Ball Material |
Stainless steel |
| Seat Material |
PTFE |
| Actuator Type |
Spring return, modulating |
| Nominal Voltage |
AC/DC 24 V |
| Control Signal |
2…10 V (4…20 mA with resistor) |
| Power Consumption (Running) |
5.5 W |
| Power Consumption (Rest) |
3 W |
| Running Time |
95 s / 90° |
| Fail-Safe Running Time |
<20 s |
| Degree of Protection |
IP54 / NEMA 2 |
| Weight |
9.1 lb |
Information About B338+AFRB24-SR
The B338+AFRB24-SR is part of Belimo’s characterized control valve family engineered to deliver stable and predictable flow control in variable-volume hydronic systems. The 3-way valve design supports both mixing and diverting applications, with optimized port geometry to maintain consistent common port flow. Its factory-installed AFRB24-SR actuator operates on AC/DC 24 V and provides precise modulating control with automatic spring return positioning during power loss. Built with corrosion-resistant materials and maintenance-free construction, the assembly is designed for long-term reliability in commercial HVAC environments.
Key Features
- Three Way Mixing And Diverting Capability: Supports flexible hydronic system design with accurate control of combined or diverted flow paths.
- Characterized Flow Performance: Equal percentage A-port and modified B-port characteristics ensure smooth modulation and stable temperature control.
- Integrated Spring Return Actuator: Automatically moves the valve to a defined safety position upon loss of power to protect system operation.
- Precise Modulating Control Input: Accepts 2…10 V control signals with optional 4…20 mA compatibility for broad controller integration.
- Durable Valve Construction: Nickel-plated brass body with stainless steel internal components provides corrosion resistance and long service life.
- Tight Shutoff Behavior: Zero leakage at A–AB and minimal leakage at B–AB support effective flow isolation when required.
- Service-Friendly Design: Manual override and mechanical position indication simplify commissioning, testing, and maintenance.
The B338+AFRB24-SR delivers the reliability and precision required for accurate three-way hydronic flow control with fail-safe performance in commercial HVAC systems.
