Quick Facts
The Belimo Z2050QPF-J+CQB24-SR-R is a 2-way, 1/2 inch press fit ZoneTight characterized ball zone valve assembly with a Cv of 5.9 and a non fail-safe modulating 2-10 vdc rotary actuator operating on 24 VAC/DC.
The forged brass valve body seats a chrome plated brass ball against a PTFE seat with EPDM O-rings for an equal percentage characteristic and a 0% leakage rate. Maximum Cv is field adjustable at the actuator end stop clip without tools, and the actuator snaps onto the valve by hand.
Specifications sourced from Belimo data sheet Z2050QPF-J (en-us, rev 2024-12-17) and assembly data sheet Z2050QPF-J+CQB24-SR-R (en-us, rev 2024-06-27).
Best For
Belimo lists the QCV zone valve for large commercial buildings where higher close-off and the ability to change flow are required, including:
- Unit ventilators
- Fan coil units
- VAV reheat coils
- Fin tube casing
- Radiant panels
- Duct coils
Warranty
Belimo warrants all components for a period of 5 years from the date of production (Belimo Zone Valves guide specification, Section 230900, revised July 22, 2025).
Key Features
Zero Leakage Ball Valve
Chrome plated brass ball on a PTFE seat with EPDM O-rings gives a 0% leakage rate and an equal percentage flow characteristic.
Field Adjustable Cv
The end stop clip sets maximum Cv in 2.5 degree increments, from 0.5 up to the full 5.9, with no special tools.
Tool-Free Snap Assembly
The actuator plugs onto the valve by hand and can be oriented in 180 degree increments. No linkage or tools required.
Low Power Brushless DC Motor
Draws 0.3 W in operation and 0.3 W at rest, with 1 VA transformer sizing.
75 Second Runtime
Non fail-safe actuator with a 75 s / 90° motor runtime over the full 90 degree rotation.
2-10 VDC Position Feedback
Provides a 2...10 V position feedback signal back to the controller.
Technical Specifications
| Specification | Value |
|---|---|
| Valve Size | 1/2 inch [DN 15] |
| Flow Pattern | 2-way |
| Pipe Connection | Press fit |
| Cv | 5.9 |
| Flow Characteristic | Equal percentage |
| Leakage Rate | 0% |
| Fluid | Chilled or hot water, up to 60% glycol |
| Fluid Temperature Range | 36 to 212 °F [2 to 100 °C] |
| Body Pressure Rating | 250 psi |
| Close-off Pressure | 75 psi |
| Max Differential Pressure | 40 psi |
| Controllable Flow Range | 75° |
| Operating Range | 15 to 90° |
| Valve Body Material | Forged brass |
| Ball Material | Chrome plated brass |
| Stem Material | Brass |
| Seat / Seals | PTFE seat, EPDM O-rings |
| Installation Orientation | Upright to horizontal |
| Servicing | Maintenance-free |
| Valve Body Weight | 0.48 lb [0.22 kg] |
| Actuator Model | CQB24-SR-R |
| Actuator Type | Non fail-safe |
| Control Signal | Modulating 2-10 VDC |
| Operating Range Y | 2...10 V |
| Operating Range Y Note | 4...20 mA w/ ZG-R01 (500 Ω, 1/4 W resistor) |
| Position Feedback U | 2...10 V |
| Signal Direction | 2 VDC Close / 10 VDC Open |
| Nominal Voltage | 24 V |
| Voltage Range | AC 19.2...28.8 V / DC 21.6...28.8 V |
| Frequency | 50/60 Hz |
| Power Consumption, Operation | 0.3 W |
| Power Consumption, Rest | 0.3 W |
| Transformer Sizing | 1 VA |
| Electrical Connection | 22 GA plenum cable, 3 ft [1 m], with 1/2" NPT conduit connector |
| Overload Protection | electronic throughout 0...90° rotation |
| Angle of Rotation | 90°, adjustable with mechanical stop |
| Running Time, Motor | 75 s / 90° |
| Noise Level, Motor | 35 dB(A) |
| Degree of Protection IEC/EN | IP40 |
| Degree of Protection NEMA/UL | NEMA 2 |
| Enclosure | UL Enclosure Type 2 |
| Ambient Temperature | 35...104°F [2...40°C] |
| Ambient Humidity | Max. 95% RH, non-condensing |
| Storage Temperature | -40...176°F [-40...80°C] |
| Agency Listing | cULus acc. to UL60730-1A/-2-14, CAN/CSA |
| CE Conformity | 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 |
| Power Source | UL Class 2 Supply |
| Actuator Weight | 0.55 lb [0.25 kg] |
| End Stop Position | Maximum Cv |
|---|---|
| Position 1 | Cv 0.5 |
| Position 2 | Cv 0.7 |
| Position 3 | Cv 1.2 |
| Position 4 | Cv 1.7 |
| Position 5 | Cv 2.4 |
| Position 6 | Cv 3.4 |
| Position N | Cv 4.8 |
| Position No end stop | Cv 5.9 |
Belimo lists the Z2050QPF-J valve body at 0.48 lb [0.22 kg] on the stand-alone data sheet (rev 2024-12-17) and 0.54 lb [0.25 kg] on the valve pages bound into the assembly data sheets (rev 2024-06-12). The value shown is from the current stand-alone data sheet.
Documentation
Frequently Asked Questions
What is the Cv rating of the Belimo Z2050QPF-J+CQB24-SR-R?
The Z2050QPF-J valve body has a Cv of 5.9. Maximum Cv is field adjustable down to 0.5 using the end stop clip on the actuator.
What pipe connection does this valve use?
Press fit. The Z2050QPF-J is a 1/2 inch [DN 15] 2-way press fit body rated 250 psi with a 75 psi close-off and 40 psi maximum differential pressure.
What control signal does the CQB24-SR-R actuator accept?
It is a modulating 2-10 vdc actuator on 24 VAC/DC.
What happens to the CQB24-SR-R on loss of power?
Nothing. This is a non fail-safe actuator with no spring or capacitor return, so the ball stays where it was when power was lost. Order a CQK series actuator if you need a fail position.
Is the CQB24-SR-R direct acting or reverse acting?
The Belimo wiring diagram shows 2 VDC Close and 10 VDC Open for this model.
Does this assembly include an auxiliary switch?
No. Order an S model actuator such as the CQKB24-S or CQKX24-S if you need a built-in end position switch.
Can the maximum flow be changed after installation?
Yes. Move the end stop clip to one of the marked positions to set maximum Cv between 0.5 and 5.9. Re-trigger adaptation on modulating actuators after any change.
- Valve Pattern:
- 2-Way
- Valve Size:
- 1/2 Inch
- Connection Type:
- Press Fit
- CV Rating:
- 5.9
- Actuator Type:
- Non Fail-Safe
- Voltage:
- 24VAC/DC
- Control Signal:
- 2-10VDC
- Auxillary Switch:
- None
