Plumbing / Valves & Fittings
Installation Guide for Danfoss NRV and NRVH Check Valves
Comprehensive installation guide for Danfoss NRV and NRVH check valves. Includes refrigerant compatibility, pressure ratings, torque settings, and soldering guidelines.
Table of contents
Quick guide from the manual
This guide provides essential installation instructions for Danfoss NRV and NRVH check valves. Key requirements include verifying refrigerant compatibility, adhering to pressure limits, and following correct mounting and connection procedures. Always ensure the design pressure meets the requirements outlined in section 9.2 of ANSI/ASHRAE 15 for the specific refrigerant used.
Refrigerant Compatibility
These valves are compatible with A1, A2, A2L, and A3 refrigerants as accepted by Danfoss. Important: R717 is excluded. Additionally, flare and face seal connections are strictly approved for A1 and A2L refrigerants only.
Installation Positions
The valves support both angleway and straightway configurations. Ensure the installation orientation aligns with the system flow requirements. The valve body features markings to indicate the correct flow direction.
Soldering and Brazing
When performing soldering or brazing, use a minimum of 5% silver (Ag) content. To prevent damage to the internal sealing materials, ensure the temperature does not exceed 155°C (311°F).
Flare Connections
For models utilizing flare connections, it is critical to apply the correct torque to ensure a secure, leak-free seal. Refer to the torque specifications table for the required Nm and ft-lbs values based on the connection size.
Special Applications
For NRV CO2 valves (90 bar) used in parallel with GBC as a pressure relief valve, the NRV must be installed above the GBC. For applications involving R744 in secondary loops or cascade systems, refer to the specific product datasheet for additional requirements.
Manufacturer information
Danfoss A/S
Practical help
Common problems
Flare/face seal connections leaking or failing.
Ensure these connection types are only used with A1 and A2L refrigerants. Verify torque settings match the connection size.
Valve damage during soldering.
Ensure the temperature does not exceed 155°C (311°F) and use a minimum of 5% silver (Ag) content.
Incorrect pressure relief setup with GBC.
When using NRV CO2 valves in parallel with GBC, install the NRV above the GBC.
Before use
- Verify that the refrigerant is compatible (A1, A2, A2L, A3, excluding R717).
- Check that the design pressure meets ANSI/ASHRAE 15 section 9.2 requirements.
- Confirm the connection type (solder or flare) is approved for the refrigerant.
- Ensure the valve orientation (angleway or straightway) matches the system layout.
- Check the maximum working pressure (PS/MWP) for your specific valve model.
Specs in practice
- Max. working pressure (PS/MWP)
- The maximum pressure the valve can withstand, ranging from 46 bar to 90 bar depending on the model.
- Media temperature range
- The operating temperature limits for the valve, typically between -50°C and 155°C.
Model compatibility
- Flare/face seal connections are restricted to A1 and A2L refrigerants only.
- R717 refrigerant is not compatible with these valves.
- For R744 (CO2) secondary loop or cascade systems, refer to the specific datasheet.
Manual page author
David Miller
Documentation analyst
Organizes user manual content into clear summaries, with attention to model details, product context, and everyday usability.