Siemens PICVs (Pressure Independent Control Valves) from the Acvatix range, including what they are, where they’re used, and full model details.
PICV = Pressure Independent Control Valve
It combines:
- A control valve (modulating or on/off)
- A differential pressure regulator
- A flow limiter (presettable Kv)
👉 It automatically maintains a constant flow rate despite pressure changes in the system, eliminating the need for separate balancing valves and ensuring perfect hydronic balancing in variable flow systems.
Why Use PICVs?
| Benefit |
Result |
| ✅ Constant flow rate |
Independent of pressure fluctuations |
| ✅ Flow pre-setting |
Ensures design flow, simplifies commissioning |
| ✅ No need for separate balancing |
Saves space and cost |
| ✅ Energy savings |
Ideal for variable speed pump systems |
| ✅ Stable control at part load |
Better comfort and system responsiveness |
Siemens PICV Valve Families (Acvatix Range)
🔹 1. Threaded PICVs – PN16 (DN15–50)
Model Series:
- VPP46… → 2-way, pressure-independent, modulating
- VPI46… → 2-way, pressure-independent, on/off (zone-level)
🔸 VPP46… (Modulating)
| Model |
DN |
Flow Range (m³/h) |
Control Signal |
Notes |
| VPP46.15-0.3 |
15 |
0.3 |
0–10 V / 3P |
Pre-settable, actuator needed |
| VPP46.15-2.5 |
15 |
Up to 2.5 |
Modulating |
Wide Kv range with SAX actuator |
| VPP46.25-6.3 |
25 |
Up to 6.3 |
Modulating |
High capacity for larger zones |
| VPP46.40-12 |
40 |
Up to 12.0 |
Modulating |
HVAC plantrooms, small AHUs |
| VPP46.50-20 |
50 |
Up to 20.0 |
Modulating |
High flow chilled/hot water |
- Body material: Brass (DN15–25), Bronze or Ductile Iron (DN32+)
- Temperature: 2–90 °C (typically)
- Actuators: SAX.. (modulating), SKD/SKC for larger valves
🔸 VPI46… (On/Off or Thermal)
| Model |
DN |
Flow Range (m³/h) |
Notes |
| VPI46.15 |
15 |
Fixed or adjustable |
Works with SFA or STA actuators |
| VPI46.20 |
20 |
~3.0 |
For fan coils, radiant panels |
| VPI46.25 |
25 |
~5.0 |
Compact zone balancing |
- Used where simple ON/OFF control is acceptable but constant flow is still needed
🔹 2. Flanged PICVs – PN25/PN40 (DN65–150)
Model Series:
- VPI55… – Larger flanged PICVs
| Model |
DN |
Flow Range (m³/h) |
Application |
| VPI55.65 |
65 |
~30–40 |
AHUs, chilled beams, floor loops |
| VPI55.100 |
100 |
~70–100 |
Central plant, large coils |
- Requires modulating actuators (SKC, GQD, etc.)
- Used in commercial HVAC systems
Actuator Compatibility
| Valve Model |
Compatible Actuators |
Control Signal |
| VPP46 DN15–25 |
SAX31 (3P), SAX61 (0–10 V) |
Modulating / 3-point |
| VPP46 DN32–50 |
SKD, SKB, SKC |
Modulating / Floating |
| VPI46 |
SFA, STA, STP |
Thermal, on/off |
| VPI55 |
SKC, GQD, SQX |
Large modulating |
Use Case Summary
| Application |
Recommended PICV Model |
| Fan coil units |
VPI46 or VPP46.15 with SFA |
| Chilled beams / VRF FCUs |
VPP46.15–25 + SAX |
| Air handling unit coil |
VPP46.40–50 + SKB/SKC |
| Plantroom, large loops |
VPI55 series + SKC |
| Energy retrofit |
VPP46 = replace 2 valves with 1 |
Bonus: Pre-assembly Option
Siemens also offers:
- Pre-assembled PICVs with actuator
- Optional insulation kits
- Labelled flow settings (manual dial or lockable caps)
ALSO CHECK OUT GLOBE VALVES
