Danfoss ASV Automatic Balancing Valves
Technical Data and Applications
Introduction
The Danfoss ASV series automatic balancing valves are designed for dynamic hydraulic balancing in heating and cooling systems. They ensure constant balancing across varying loads (0-100%) by controlling differential pressure in variable flow systems. This dynamic balancing simplifies system setup, reduces energy consumption, and improves climate control comfort.
Key Features and Benefits
- Dynamic Hydraulic Balancing: Maintains system balance under all load conditions.
- Pressure Independent Control: Ensures precise and stable operation, leading to energy savings.
- Noise Reduction: Prevents pressure increases at control valves, reducing noise levels, as required by standards like DIN 18380.
- Simplified Setup: Eliminates the need for complex balancing procedures, saving time and cost.
- Compact Design: Small, integrated modules allow for easy installation even in tight spaces.
- Service Functions: Features like shut-off, draining, and measurement ports are integrated.
ASV Valve Types
The ASV range includes several types, each with specific functionalities:
- ASV-P: Fixed differential pressure setting (typically 10 kPa), adjustable to 20 or 30 kPa by changing the spring.
- ASV-PV: Offers adjustable differential pressure settings, commonly used for radiators, fan coil units, and apartment stations, with ranges like 5-25 kPa, 20-40 kPa, 35-75 kPa, and 60-100 kPa.
- ASV-BD: A shut-off valve with pre-setting functionality, used as a companion valve.
- ASV-I: A regulating valve with two measurement ports, also used as a companion valve.
- ASV-M: A shut-off valve, used as a companion valve.
Diagrams on pages 1, 2, 3, 4, 11, 12 illustrate the different valve types and their configurations.
Applications
ASV valves are suitable for various applications:
- Riser balancing in heating and cooling systems.
- Flow limitation at terminal units (e.g., radiators) in conjunction with pre-setting valves.
- Floor heating systems to control flow per circuit.
- Fan coil units and air handling units for automatic hydraulic balancing.
- Apartment stations to manage differential pressure under different operating conditions (heating and domestic hot water).
- Preventing noise issues in small systems with thermostatic radiator valves.
Figures on pages 3 and 4 show typical application examples for heating risers, floor heating, fan coil units, and apartment stations.
Technical Data Summary
Key technical specifications include:
- Nominal Diameter (DN): 15-100 mm.
- Maximum Operating Pressure: 16 bar (PN 16).
- Test Pressure: 25 bar.
- Differential Pressure Range: Varies by valve type, typically 10-150 kPa for ASV-I/M/P/PV and 10-250 kPa for ASV-BD.
- Temperature Range: -20°C to 120°C (depending on DN size).
- Materials: Valve body typically brass or grey cast iron, internal parts brass or stainless steel, diaphragm EPDM.
Detailed specifications are available in tables on pages 8, 16, 17, 18, 24.
Sizing and Selection
Sizing of ASV valves is performed using diagrams provided in Appendix A (Figures A, B, C, D, E on pages 19-22). These diagrams relate flow rate (Q), differential pressure (Δp), and valve size (DN) using Kvs values. The selection process involves determining the required flow and pressure drop to select the appropriate valve size and setting.
Figure 7 on page 5 provides a general sizing diagram for ASV-P/PV valves.
Construction and Components
The ASV valves feature a robust construction with key components including:
- Valve Body: Houses internal components.
- Diaphragm Element: Regulates pressure.
- Pressure-Relieved Cone: For pressure control.
- Spindle and Shut-off Handle: For manual operation and shut-off.
- Impulse Tube Connection: For differential pressure sensing.
- Measurement Ports: For flow and pressure measurement.
- Springs: For setting differential pressure ranges.
Detailed exploded views and component lists are available on pages 8, 9, 10, 11, 12.
Installation and Commissioning
Installation: ASV-P/PV valves are typically mounted on the return pipe, while companion valves (ASV-M/I/BD) are mounted on the supply pipe. The impulse tube connects the companion valve to the ASV-P/PV. Proper orientation is indicated by flow arrows on the valve body.
Commissioning: When filling the system, ensure static pressure is equal on both sides of the diaphragm to prevent damage. This may involve opening companion valves before ASV-P/PV or ensuring the correct sequence for filling.
Further details on installation and commissioning are provided on pages 11 and 15.
Insulation and Fittings
Insulation: The original EPS packaging can be used for insulation up to 80°C. EPP insulation covers are available for higher temperatures (up to 120°C). Both materials meet fire safety class B2 according to DIN 4102.
Fittings: Danfoss offers various fittings, including threaded nipples and welding nipples, made from brass or steel, to connect valves with external threads.
Information on insulation and fittings, including ordering codes, is on page 23. Dimension tables for insulation are on page 24.
Ordering Information
The document includes extensive tables detailing ordering codes for various ASV valve types, companion valves, insulation covers, and fittings. These tables specify model numbers, DN sizes, connection types (threaded, flanged), and specific settings.
Refer to pages 6, 7, 16, 17, 18, 23 for detailed ordering information.
