The Belimo Z2050Q-J is a 2-way 1/2 in. NPT characterized control ball valve from the Belimo ZoneTight (QCV) series, rated Cv 5.9 with 0% leakage, 75 psi close-off and a 360 psi body. The actuator is ordered separately and snaps on without tools.
The valve body suits closed chilled and hot water systems with up to 60% glycol. Maximum flow is set in the field by moving the end stop clip on the actuator, so one body covers a Cv range from 0.5 up to the nominal 5.9.
Specifications on this page are taken from belimo_Z2050Q-J_datasheet_en-us.pdf (valve data rev. 2024-12-17). Figures are as published by Belimo and are subject to change.
Best For
Belimo lists the QCV zone valves for large commercial buildings where higher close-off and field-adjustable flow are wanted. Documented applications are unit ventilators, fan coil units, VAV reheat coils, fin tube casing, radiant panels and duct coils.
Warranty
Belimo warrants all components for 5 years from the date of production. Note that exceeding the 212°F fluid temperature limit voids the manufacturer warranty even though the valve will safely contain the water.
Key Features
Field-Adjustable Cv
Maximum flow is set by moving the end stop clip in 2.5° increments, giving a Cv from 0.5 to the nominal 5.9 without changing the valve body.
Zero Leakage Shutoff
Leakage rate is 0% with 75 psi close-off, so the coil is fully isolated during unoccupied periods and no energy is lost through a seeping valve.
Tool-Free Snap Assembly
The actuator plugs onto the valve flange by hand, and mounting orientation can be turned in 180° increments. No linkage or tools are required.
Forged Brass Ball Construction
Forged brass body, chrome-plated brass ball, PTFE seat and double EPDM O-rings. Ball valve construction resists the clogging that affects globe-style seats.
Takes CQ or CQK Actuators
Belimo lists CQB(X) non fail-safe and CQKB(X) electronic fail-safe actuators as suitable for this body, so the control strategy can be chosen separately.
Equal Percentage Characteristic
The characterizing disc gives an equal percentage flow curve across a 75° controllable range, which matches the output curve of a hydronic coil.
Technical Specifications
Valve Body
| Valve pattern | 2-way |
| Valve size | 0.5" [15 mm], DN 15 |
| Cv | 5.9 |
| Pipe connection | Internal thread, NPT (female) |
| Fluid | Chilled or hot water, up to 60% glycol |
| Fluid temperature range | 36...212°F [2...100°C] |
| Body pressure rating | 360 psi |
| Close-off pressure | 75 psi |
| Differential pressure max | 40 psi |
| Flow characteristic | Equal percentage |
| Leakage rate | 0% |
| Controllable flow range | 75° |
| Angle of rotation | Operating range 15...90° |
| Installation orientation | Upright to horizontal (in relation to the spindle) |
| Servicing | Maintenance-free |
| Valve body material | Forged brass |
| Ball | Chrome plated brass |
| Stem | Brass |
| Stem seal | EPDM O-ring |
| Seat | PTFE with EPDM O-ring |
| O-ring | EPDM (lubricated) |
| Valve body weight | 0.37 lb [0.17 kg] |
Valve body weight is the current TDS rev 2024-12-17 figure. The superseded assembly PDFs rev 2024-06-12 list 0.35 lb [0.16 kg].
End Stop Clip Positions
Maximum flow is set by moving the end stop clip. Values below are Belimo published V'max figures for the Z2050Q-J. Runtimes shown are for 75 s actuators.
| Clip position | Cv (V'max) | Runtime |
|---|---|---|
| 1 | 0.5 | 30 s |
| 2 | 0.7 | 37 s |
| 3- | Not available | 41 s |
| 3 | 1.2 | 43 s |
| 4 | 1.7 | 49 s |
| 4+ | Not available | 51 s |
| 5 | 2.4 | 55 s |
| 5+ | Not available | 58 s |
| 6 | 3.4 | 62 s |
| N | 4.8 | 68 s |
| No end stop | 5.9 | 75 s |
Source: Belimo Quick Mount Visual Instruction Manual 71775-00001.L / 71694-00001.K.
Documentation
Z2050Q-J Valve Technical Data Sheet- CQ Actuator Quick Mount Instruction Manual
- CQK Actuator Quick Mount Instruction Manual
- Belimo ZoneTight Zone Valve Brochure
- Belimo Zone Valve Guide Specifications
Frequently Asked Questions
What is the Cv of the Belimo Z2050Q-J?
The nominal Cv is 5.9 with no end stop clip fitted. Belimo publishes reduced Cv values of 4.8, 3.4, 2.4, 1.7, 1.2, 0.7 and 0.5 for the selectable clip positions, so maximum flow can be set in the field without changing the valve.
Will the Z2050Q-J shut off completely?
Yes. Belimo rates the valve at 0% leakage with a close-off pressure of 75 psi and a body pressure rating of 360 psi.
What fluids and temperatures does it handle?
Chilled or hot water with up to 60% glycol, over a fluid temperature range of 36 to 212°F (2 to 100°C). Exceeding 212°F voids the manufacturer warranty.
Does this part number include an actuator?
No. This is the valve body only. Belimo lists the CQB(X) non fail-safe and CQKB(X) electronic fail-safe actuators as suitable, and they snap on by hand.
Can the valve be mounted in any orientation?
It can be installed upright through horizontal. Belimo prohibits hanging installation with the stem pointing downwards.
Other Z2050Q-J Configurations
Z2050Q-J.1 · Z2050Q-J+CQB24-3 · Z2050Q-J+CQB24-SR-L · Z2050Q-J+CQB24-SR-R · Z2050Q-J+CQBUP-3 · Z2050Q-J+CQKB24-LL · Z2050Q-J+CQKB24-RR · Z2050Q-J+CQKB24-S-LL
Belimo warrants all components of the ZoneTight valve and actuator assembly for 5 years from the date of production. Warranty terms are stated in the Belimo Zone Valve Guide Specifications (rev. July 22, 2025). Operating the valve above its 212°F fluid temperature rating voids the manufacturer warranty.
- Valve Pattern:
- 2-Way
- Valve Size:
- 1/2 Inch
- Connection Type:
- NPT
- CV Rating:
- 5.9
- Actuator Type:
- Valve Only
