The difference between the Siemens VVG41 and VVG44 valves lies primarily in their control type and intended application. Here’s a breakdown:
VVG41 – 2-Way Control Valve (Standard Range) 
- Type: 2-way valve
- Control: Typically on/off or floating control
- Operation: Designed for use with thermal or electro-mechanical actuators
- Application: General HVAC water systems – chilled or heating water
- Connection: Internally threaded (usually Rp thread)
- Body Material: Often bronze or brass
- DN Sizes: Commonly DN15 to DN50
- Pressure Rating: PN16 or similar
VVG44 – 2-Way Control Valve (High-Performance Range) 
- Type: 2-way valve
- Control: Designed for modulating control
- Operation: Paired with electronic modulating actuators (e.g., SAX, SKD/SKP)
- Application: More precise flow control needed – typically used in systems requiring accurate temperature regulation
- Connection: Also usually internally threaded
- Body Material: Higher-grade materials (often bronze or special alloys)
- Flow Characteristic: Often equal percentage
- Pressure Rating: Higher precision, may have tighter leakage rates and stroke tolerances
Quick Summary:
Feature | VVG41 | VVG44 |
---|---|---|
Valve type | 2-way | 2-way |
Control | On/Off or Floating | Modulating |
Actuator type | Thermal, electro-mechanical | Modulating electronic |
Application | Basic HVAC | Precision HVAC control |
Flow characteristic | Linear or not specified | Equal percentage (better control) |
Use with… | STA/STP actuators | SAX/SKD/SKP actuators |
If you need help selecting a replacement or actuator pairing, feel free to share the model number, application, or flow requirements. Send us an enquiry in the attached link