Round duct connector with check valve airRoxy 125 (coupling)

The round duct connector with check valve airRoxy 125 is a coupling designed for 125 mm circular ventilation ducts. It combines a secure mechanical connection with an integrated one-way valve that prevents backflow. The component is intended for use in residential and light-commercial ventilation systems, in both exhaust and supply air lines, and in retrofit installations where controlled directional airflow is needed.

Advantages

This coupling provides a compact solution that integrates a check valve into a standard round connector, reducing the number of separate components and installation steps. Its design ensures a firm fit on 125 mm ducts and reliable prevention of reverse airflow, helping maintain intended ventilation patterns. The product is suitable for tight spaces and for cases where a retrofit check valve is required without changing the existing duct layout.

Suitable for

• 125 mm circular ventilation ducts
• Residential mechanical ventilation systems (exhaust or supply)
• Light-commercial ventilation and HVAC applications
• Retrofit installations requiring one-way airflow control
• Bathroom, kitchen or utility exhaust lines to prevent backdraft

Key specifications

• Designed for nominal duct diameter: 125 mm
• Integrated one-way (check) valve for backflow prevention
• Coupling type: round duct connector
• Suitable for supply and exhaust air applications
• Compact form factor for retrofit and confined spaces

How to use

Insert the coupling into the corresponding 125 mm circular duct ends and ensure a secure fit by pushing the connector fully onto both duct sections. If required, apply appropriate sealing material or tape at the joints to improve airtightness according to local installation practices. The integrated check valve is ready-mounted and will operate automatically to allow airflow in the intended direction and close to prevent reverse flow. No separate valve assembly is necessary.

Usage recommendations

For reliable performance, check the orientation of the coupling before finalizing the installation so the check valve faces the correct airflow direction. Periodically inspect the valve area for dust buildup or obstruction and clean as needed during routine ventilation maintenance. When used in humid or grease-prone environments, consider additional corrosion-resistant ducting or regular cleaning to preserve valve operation.