Aftercooling two-way valve in insulation DBV 2
The two-way thermostatic aftercooling valve is designed for aftercooling solid fuel boilers without aftercooling exchanger. When the temperature reaches 97 °C, the valve opens the cooling water supply from the water supply system. This cools the boiler, thereby preventing it from overheating. The hot water is discharged into the sewer and at the same time the pressure water inlet valve from the water supply system opens. When the temperature drops below the limit, both valves close simultaneously.
The drain and inlet valve in the brass body is controlled by 2 thermostatic elements. For proper function, the valve must be placed where the temperature is highest when the boiler overheats - usually directly in the upper part of the boiler or on the outlet pipe in close proximity to the boiler. Thermostatic elements from a renowned French manufacturer are placed directly in the heating water, thanks to which the reaction to changes in the temperature of the heating water is practically immediate. The valve has a button for manual opening (similar to safety valves)
If the outlet pressure from the water supply system is higher than 6 bar, it is necessary to install a pressure reducing valve on the cooling water inlet. It is also necessary to install it when the pressure in the heating system is too high after cooling. In these cases, we recommend setting the pressure on the pressure reducing valve to approximately twice the pressure required in the heating system, but at least 2 bar.
The valve is approved according to Directive 97/23/EC (PED) and its design meets the requirements for a device for removing excess heat according to Art. 4.3.8.4 STN EN 303-5:2012. This is a STW type Th device according to STN EN 14597:2012. According to STN EN 303-5:2012, the valve is intended for boilers with a maximum output of 500 kW with a cooling output of up to 100 kW. Installation may only be carried out by a qualified person.
Nominal diameter: DN20
Boiler connection: R 3/4" external
Pipe connection: G 3/4" external
Max. working pressure of heating fluid: 4 bar
Max. working pressure of cold water: 6 bar
Max. working temperature of fluid: 110 °C
Valve opening temperature: 97 °C
Hysteresis: 2°C
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