Thermostatic radiator valve straight DN20 with presetting DANFOSS 90482000521

Straight thermostatic radiator valve DN20 by DANFOSS with factory presetting is engineered for precise flow control in hot-water heating systems. The valve is designed to be fitted in-line on radiators with DN20 connections to regulate the amount of heating medium delivered to each radiator. Factory presetting enables predictable flow rates and simplified hydraulic balancing, supporting stable room temperatures and efficient system operation.

Advantages

The valve provides stable temperature control through accurate flow limitation and works with standard thermostatic heads for individual room regulation. Factory presetting reduces the need for on-site calibration, speeding installation and ensuring consistent performance across multiple radiator circuits. Its straight design allows straightforward installation in typical radiator piping runs, and compatibility with DN20 fittings ensures broad applicability in residential and commercial heating systems.

Suitable for

• Individual room temperature regulation in residential radiators
• Hydraulic balancing of hot-water heating systems
• Replacement or upgrade of existing DN20 radiator valves
• Commercial premises with DN20 radiator connections

Key specifications

• Connection type: straight in-line valve for radiator connection
• Nominal size: DN20 suitable for standard 20 mm radiator fittings
• Function: thermostatic control with factory presetting for predefined flow rates
• Use: intended for hot-water (hydronic) central heating systems
• Compatibility: designed to work with standard thermostatic actuator heads

How to use

Install the DN20 straight valve into the radiator supply or return line following the pipeline flow direction indicated on the valve body. Use the factory presetting to set the desired maximum flow for each radiator; final fine-tuning can be achieved by adjusting the thermostatic head. After installation, bleed the radiator and check for leaks. Commission the system by opening the thermostatic head and confirming that the radiator reaches the expected temperature while the valve maintains the preset flow balance across the system.

Usage recommendations

For reliable operation, pair the valve with a compatible thermostatic head from the same product family and perform hydraulic balancing during system commissioning. Regular visual inspections and occasional leak checks are recommended, and any maintenance or replacement should be performed with the heating system depressurised.