RPZ - backflow preventer by:
The backflow preventer is a hydraulic protection device designed to prevent polluted water from flowing back into the mains supply network. This type of backflow may occur when the pressure in the mains supply network changes and causes a reversal of the flow. The backflow preventer is installed between the mains supply network and the internal consumer circuit in water supply systems and creates a safety zone which prevents the water in the two circuits from coming into contact.
Backflow preventers must be installed by qualified personnel in accordance with current regulations.
They must be installed downstream from a shut-off valve and from a strainer with a discharge that can be inspected and another shut-off valve
must be fitted downstream from it. The unit must be installed in an accessible position, appropriately located to avoid possible immersion due
to accidental flooding (see diagram).
The device must be fitted horizontally. The discharge tundish must comply with standard EN 1717 and be connected to the sewage piping.
Before installing the backflow preventer and the strainer, the pipework must be flushed with a large flow rate.
When used to protect the mains supply network, backflow preventers must be installed downstream from the water meter, whereas when used
to protect the potable water supply system for internal usage, they are installed at the limit of the zone where pollution might occur, e.g. central
heating systems, garden irrigation systems, etc.