The Belimo Z2100QS-K+CQKB24-S-LL is a 2-way, 1" sweat ZoneTight (QCV) zone valve assembly that pairs the Z2100QS-K forged brass ball valve (Cv 8.2, 75 psi close-off, 0% leakage) with the Belimo CQKB24-S-LL electronic fail-safe actuator for on/off control at 24 VAC/DC, driving to the open position on power loss.
Specifications per Belimo Z2100QS-K technical data sheet (2024-06-12) and CQKB24-S-LL technical data sheet (2024-03-15).
Best for
- Two-position zone control from a thermostat or on/off controller output
- Unit ventilators, fan coil units and VAV reheat coils
- Fin tube casing, radiant panels and duct coils
- Closed chilled-water and hot-water systems, up to 60% glycol
- Zones that must fail open on loss of power
- Applications needing end-position indication, interlock or fan startup from an aux switch
Key Features
Zero-leakage ball valve
Forged brass body with chrome plated brass ball, 0% leakage, equal-percentage flow and 75 psi close-off.
Field-adjustable Cv
The end stop clip limits maximum flow, with selectable end stop settings from Cv 0.5 to 8.2, set without tools.
Electronic fail-safe
Drives to the open position on power loss after a 2 s bridging time; fail-safe running time <60 s.
On/Off control
Two-position operation with a 75 s / 90° running time.
Built-in aux switch
1x SPST, 1 A resistive auxiliary switch for end position indication, interlock control or fan startup.
Tool-free snap assembly
Actuator snaps onto the valve by hand, mounts in 180° increments and lifts straight off for service.
ZOT Supply is an authorized distributor of Belimo products.
Technical Specifications
| Specification | Value |
|---|---|
| Assembly Part Number | Z2100QS-K+CQKB24-S-LL |
| Valve Model | Z2100QS-K |
| Valve Series | ZoneTight (QCV) zone valve |
| Valve Size | 1" [DN 25] |
| Pipe Connection | Sweat |
| Flow Pattern | 2-way |
| Cv (full open) | 8.2 |
| Field-Adjustable Cv | Selectable end stop settings, Cv 0.5 to 8.2 |
| Flow Characteristic | Equal percentage |
| Leakage Rate | 0% |
| Body Pressure Rating | 360 psi |
| Close-off Pressure | 75 psi |
| Max. Differential Pressure | 40 psi |
| Fluid | Chilled or hot water, up to 60% glycol |
| Fluid Temperature | 36...212°F [2...100°C] |
| Valve Body | Forged brass |
| Ball | Chrome plated brass |
| Stem | Brass |
| Stem Seal | EPDM O-ring |
| Seat | PTFE, O-ring EPDM |
| Flow Direction | Both directions |
| Installation Orientation | Upright to horizontal (not stem down) |
| Servicing | Maintenance-free |
| Valve Weight | 1.2 lb [0.54 kg] |
| Actuator Model | CQKB24-S-LL |
| Actuator Type | Electronic fail-safe |
| Control | On/Off |
| Fail Position | Open |
| Auxiliary Switch | 1x SPST, 1 A resistive |
| Nominal Voltage | AC/DC 24 V |
| Nominal Voltage Range | AC 19.2...28.8 V / DC 21.6...28.8 V |
| Frequency | 50/60 Hz |
| Power Consumption, Operation | 2.5 W |
| Power Consumption, Rest | 0.5 W |
| Transformer Sizing | 5 VA |
| Electrical Connection | 22 GA plenum cable, 3 ft [1 m], with 1/2" NPT conduit connector |
| Running Time (Motor) | 75 s / 90° |
| Bridging Time (Power Fail) | 2 s |
| Pre-charging Time | 5...20 s |
| Running Time, Fail-Safe | <60 s |
| Angle of Rotation | 90° |
| Rotation Adjustment | Adjustable with mechanical stop |
| Noise Level, Motor | 35 dB(A) |
| Position Indication | 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 |
| 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 Plenum Rating | 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 | 0.57 lb [0.26 kg] |
Documentation
Belimo Z2100QS-K+CQKB24-S-LL Technical Data Sheet Belimo Z2100QS-K Valve Technical Data Sheet Belimo CQK Actuator with ZoneTight Valve Installation Instructions Belimo ZoneTight Valve Brochure Belimo Zone Valve Guide SpecificationFrequently Asked Questions
What is the Cv of the Belimo Z2100QS-K+CQKB24-S-LL?
The Z2100QS-K valve has a Cv of 8.2 at full open. The end stop clip positions limit maximum flow to Cv 0.5, 0.9, 1.5, 2.2, 3.1, 4.3, 6 and 8.2 with no end stop.
What close-off pressure is the valve rated for?
75 psi close-off, 40 psi maximum differential pressure and a 360 psi body pressure rating.
How is the actuator controlled?
On/Off control from a switched 24 VAC/DC supply, with a motor running time of 75 s / 90°.
What happens on a power failure?
After a 2 s bridging time the actuator drives the valve open, with a fail-safe running time of <60 s. Pre-charging time is 5...20 s.
What transformer size is required?
Size the supply at 5 VA per actuator. Power consumption is 2.5 W in operation and 0.5 W at rest.
What is the auxiliary switch rating?
The built-in switch is 1x SPST, 1 A resistive, for end position indication, interlock control or fan startup.
What fluids and temperatures can it handle?
Chilled or hot water with up to 60% glycol, at fluid temperatures of 36...212°F [2...100°C].
- Valve Pattern:
- 2-Way
- Valve Size:
- 1 Inch
- Connection Type:
- Sweat
- CV Rating:
- 8.2
- Max Close-Off Pressure:
- 75 psi
- Max Operating Pressure:
- 360 psi
- Medium Temperature Range:
- 36-212 °F
- Body Material:
- Forged Brass
- Actuator Type:
- Fail-Safe
- Fail-Safe Position:
- Fail Open
- Voltage:
- 24VAC/DC
- Control Signal:
- On/Off
- Auxillary Switch:
- (1) SPST 1A @ 30VDC
- Power Connection:
- Plenum Cable
