A safety group combines several components with different functions in one device. It is installed between the cold water network and the hot water storage tank. The unit should be as close as possible to the storage tank. Each safety group has at least one safety valve and one backflow preventer, but may also include other components.
If the set pressure in the storage tank is exceeded, the valve opens and allows excess water to drain. When the desired pressure is reached, the valve closes again.
If the safety valve opens, the backflow preventer stops the expanded and possibly contaminated water from flowing into the drinking water network. This prevents the contamination of the drinking water. However, water is always lost in the process, which can lead to increased costs if the safety group is used frequently.
The pressure reducer is usually already attached to the house connection and is therefore possibly not mandatory. It regulates the pressure in the drinking water network and thus prevents an already filled water storage tank from being loaded even more.
It allows to read the pressure in a reservoir. The manometer is usually built in and is available in several versions: as a nozzle or readable indicator with a needle.
They shut off individual components of the safety group, thus simplifying maintenance.
The expansion vessel is a separate chamber attached to the safety valve, into which the water causing the overpressure is directed before it is finally drained off. On the one hand, a buffer is formed which relieves the valve and, on the other hand, the excess water is not directly wasted, which in turn saves costs.