In a closed-loop hot water installation, the water expands as it heats up. If this excess volume is not met by the closed expansion tank with membrane (diaphragm), the pressure rises and the safety valve opens. This tool calculates the required tank volume, the pre-pressure of the tank and the cold filling pressure according to the TS EN 12828 method.
Formula
And = e · Vsistem p₀ = Hstatic / 10.2 + 0.2 bar pe = psafety − 0.5 bar
e: the expansion rate of water between filling and the highest operating temperature (from IAPWS-IF97 densities), Vwr: water reserve (0.5% of the system volume, at least 3 L).
Example
An installation with a water volume of 2,000 liters, filled at 10 °C and operating at 90 °C, with a static height of 10 m and a safety valve of 3 bar, has an expansion rate of 3.56% and an expansion volume of 71 L. The required tank volume is 216 L, the recommended standard tank is 250 L. The tank pre-pressure should be 1.18 bar and the cold filling pressure should be 1.29 bar.
If you do not know the installation water volume, you can calculate it with the installation water volume tool . You can consult Çiftel Kazan engineers for your boiler room and installation project.