Siemens VQI46 On/Off Pressure Independent Control Valve, Female Thread, PN25
Siemens VQI46 Internally Threaded On/Off Pressure-Independent Control Valve PN25
The Siemens VQI46 series belongs to the pressure-independent control valve (PICV) family: flow presetting, a differential pressure regulator and an on/off valve are combined in one body. Available in sizes DN15–DN25 with internal thread connection. The set maximum flow is not affected by pressure fluctuations in the system, so hydronic balance in fan coil, air handling unit and heating/cooling circuits is achieved without a separate balancing valve. Medium temperature range is 1…90 °C.
The last number in the model code shows the approximate nominal flow in m³/h (e.g. VQI46.25F1.8); the nominal flow of each model is given in the model table. The valve operates with an actuator of suitable stroke and positioning force; verified actuators are listed below.
Models and order codes
| Model | DN | Nominal flow rate | PN | Connection | Stroke | Order code |
|---|---|---|---|---|---|---|
| VQI46.15F1.3 | DN15 | 1300 l/h | PN25 | Rp ½" | 4 mm | S55264-V140 |
| VQI46.15F1.3Q | DN15 | 1300 l/h | PN25 | Rp ½" | 4 mm | S55264-V139 |
| VQI46.20F1.5Q | DN20 | 1500 l/h | PN25 | Rp ¾" | 4 mm | S55264-V143 |
| VQI46.25F1.8 | DN25 | 1800 l/h | PN25 | G 1¼" | 4 mm | S55264-V148 |
Technical specifications
| Specification | Value |
|---|---|
| Number of ways | 2 |
| Connection type | Internal thread |
| Body material | DZR brass |
| Ambient temperature | 1…50 °C |
| Medium temperature | 1…90 °C |
| Medium type | Hot water |
Compatible products
- Siemens STA Thermal (Thermoelectric) Valve Actuator — STA161.65L10, STA321.65L10
- Siemens SUE21P Electromotive Valve Actuator 100 N, 230 V — SUE21P
- Siemens ALG Valve Connection Fitting Sets (DN20–DN40) — ALG202
This list is verified compatibility information based on Siemens product matching data; it is not a list of similar-product suggestions. You can make the final selection with our engineering team based on your project conditions (differential pressure, stroke, control signal).
Selection and installation notes
- Selection is based on the design flow rate of the circuit; the flow rate is set on the valve and is maintained even when the pressure changes.
- For the valve to work properly, at least the minimum differential pressure must be available across it (the value is given in the data sheet).
- The actuator is selected taking into account the valve stroke and the control signal (on/off or modulating).
Technical documents
You can find them on the manufacturer's website by searching for the Siemens document number:
- A6V11877580 — Datasheet (English)
- A6V11878322 — Datasheet (German)
- A6V11893435 — Data sheet (English)
- A6V14451271 — Test report (EN 10204) (English)
- A6V15489263 — Environmental product declaration (EPD) (English)
For the right model selection and wholesale or project pricing, contact the Novus Energy engineering team on our WhatsApp line.