Water seal of a diaphragm expansion vessel
The water reserve of a diaphragm expansion vessel is the minimum water level in the vessel and must compensate for the volume that arises due to system-related water losses. The water reserve must be at least 0.5 % of the system volume if the nominal volume of the diaphragm expansion vessel is greater than 15 litres. If the nominal volume of the diaphragm expansion vessel is less than 15 litres, the water reserve must be at least 20 % of the system volume.
Note:
However, the water reserve must never be less than 3 litres.
Symbol or abbreviation: | VV |
Usual unit: | l |
| Equation: | For diaphragm expansion vessels with a nominal volume of more than 15 litres: VV=0.005*VA For diaphragm expansion vessels with a nominal volume of less than 15 litres: VV=0.2*VA |