The Belimo Z2075Q-K+CQKB24-SR-RL is a 3/4 in. NPT, 2-way ZoneTight (QCV) zone valve assembly that pairs the Z2075Q-K valve (Cv 9.8, 0% leakage) with the CQKB24-SR-RL electronic fail-safe actuator for modulating 2...10 V control at AC/DC 24 V: 2 VDC = Close, 10 VDC = Open; fail position 100% Open.
The ball valve closes off against 75 psi and handles chilled or hot water with up to 60% glycol from 36 to 212°F. The body is forged brass with a chrome plated brass ball and a 360 psi body pressure rating. The actuator snaps onto the valve by hand, with no tools or linkage.
Best For
- Unit ventilators
- Fan coil units
- VAV reheat coils
- Fin tube casing
- Radiant panels
- Duct coils
- Large commercial buildings where higher close-off and the ability to change flow is needed
- Space-restricted installations
Warranty
Belimo warrants ZoneTight zone valve components for 5 years from the date of production. If fluid temperature exceeds the 212°F operating range because of a boiler control failure, the valve will safely contain the hot water but the manufacturer warranty becomes invalid.
Key Features
0% leakage ball valve
Chrome plated brass ball on a PTFE seat with EPDM O-rings: 0% leakage and an equal percentage flow characteristic.
Field-adjustable maximum flow
The end stop clip on the actuator changes the angle of rotation in 2.5° increments, setting the maximum Cv from 0.5 to 9.8.
Tool-free snap assembly
The actuator plugs onto the valve by hand, with the mounting orientation selectable in 180° increments.
Electronic fail-safe
On loss of power the actuator runs to fail position 100% Open in <60 s.
Modulating with feedback
Accepts 2...10 V (4...20 mA with the ZG-R01 500 Ω resistor) and returns a 2...10 V position feedback signal.
Low power draw
2.5 W in operation, 0.5 W at rest; size the transformer at 5 VA.
ZOT Supply is an authorized distributor of Belimo products.
Technical Specifications
Valve
| Valve model | Z2075Q-K |
| Valve type | ZoneTight (QCV) zone valve, 2-way, NPT |
| Cv (no end stop) | 9.8 |
| Nominal size | 3/4 in. [DN 20] |
| Pipe connection | Internal thread NPT (female) |
| Flow pattern | 2-way |
| Flow characteristic | Equal percentage |
| Leakage rate | 0% |
| Fluid | Chilled or hot water, up to 60% glycol |
| Fluid temperature range (water) | 36...212°F [2...100°C] |
| Body pressure rating | 360 psi |
| Close-off pressure (Δps) | 75 psi |
| Differential pressure (Δpmax) | 40 psi |
| Operating range (angle of rotation) | 15...90° |
| Controllable flow range | 75° |
| Flow direction | Both directions possible |
| Installation orientation | Upright to horizontal; not hanging with the stem pointing downwards |
| Valve body | Forged brass |
| Ball | Chrome plated brass |
| Stem | Brass |
| Stem seal | EPDM O-ring |
| Seat | PTFE, O-ring EPDM |
| O-ring | EPDM (lubricated) |
| Servicing | Maintenance-free |
Actuator
| Actuator model | CQKB24-SR-RL |
| Actuator type | Modulating, Electronic fail-safe, 24 V |
| 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 | 2.5 W |
| Power consumption in rest position | 0.5 W |
| Transformer sizing | 5 VA |
| Electrical connection | 22 GA plenum cable, 3 ft [1 m], with 1/2 in. NPT conduit connector |
| Operating range Y | 2...10 V |
| Operating range Y, 4...20 mA | 4...20 mA w/ ZG-R01 (500 Ω, 1/4 W resistor) |
| Feedback signal U | 2...10 V |
| Bridging time (PF) | 2s |
| Pre-charging time | 5...20 s |
| Angle of rotation | 90° |
| Angle of rotation adjustment | adjustable with mechanical stop |
| Running time (motor) | 75 s / 90° |
| Running time (fail-safe) | <60 s |
| Noise level, motor | 35 dB(A) |
| Noise level, fail-safe | 35 dB(A) |
| Visual indicator | pointer |
| Overload protection | electronic throughout 0...90° rotation |
| Electrical protection | actuators are double insulated |
| Power source UL | Class 2 Supply |
| Degree of protection IEC/EN | IP40 |
| Degree of protection NEMA/UL | NEMA 2 |
| Enclosure | 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 |
| UL 2043 compliant | Suitable for use in air plenums per Section 300.22(C) of the NEC and Section 602 of the IMC |
| Ambient temperature | 35...104°F [2...40°C] |
| Ambient humidity | Max. 95% RH, non-condensing |
| Storage temperature | -40...176°F [-40...80°C] |
| Housing material | UL94-5VA |
| Actuator weight | 0.55 lb [0.25 kg] |
| Control action | 2 VDC Close, 10 VDC Open |
| Fail position | 100% Open |
Maximum Cv by end stop clip position
| Clip position | 1 | 2 | 3 | 4 | 5 | 6 | N | No end stop |
|---|---|---|---|---|---|---|---|---|
| Max Cv | 0.5 | 1.0 | 1.5 | 2.3 | 3.3 | 4.6 | 6.6 | 9.8 |
| Runtime (s) | 30 | 37 | 43 | 49 | 55 | 62 | 68 | 75 |
Specifications per Belimo Z2075Q-K technical data sheet rev 2024-06-12, CQKB24-SR-RL technical data sheet rev 2024-06-27, CQK Quick Mount manual 71775-00001.L. Reviewed 2026-09-24.
Documentation
FAQ
What is the Cv of the Belimo Z2075Q-K+CQKB24-SR-RL?
9.8 with no end stop. Moving the end stop clip sets a lower maximum Cv of 0.5, 1.0, 1.5, 2.3, 3.3, 4.6 or 6.6.
What size and pipe connection is the Belimo Z2075Q-K?
3/4 in. (DN 20), internal thread NPT (female). The forged brass body is rated 360 psi, with a 75 psi close-off and 40 psi maximum differential pressure.
What fluids and temperatures can the Z2075Q-K handle?
Chilled or hot water with up to 60% glycol, at fluid temperatures of 36...212°F [2...100°C].
What control signal does the Belimo CQKB24-SR-RL actuator use?
Modulating 2...10 V, on AC/DC 24 V. A 4...20 mA signal can be used with the ZG-R01 500 Ω resistor.
What is the fail position of the Belimo CQKB24-SR-RL?
Fail position 100% Open. On loss of power the actuator runs to that position in <60 s.
Which control signal opens the valve on the Z2075Q-K+CQKB24-SR-RL?
2 VDC = Close, 10 VDC = Open.
- Valve Pattern:
- 2-Way
- Valve Size:
- 3/4 Inch
- Connection Type:
- NPT
- CV Rating:
- 9.8
- Actuator Type:
- Fail-Safe
- Voltage:
- 24VAC/DC
- Control Signal:
- 2-10VDC
- Auxillary Switch:
- None
