Check valves, also referred to as backflow preventers, are used in sanitary and building faucets of drinking water installations. They keep the pipework free of unwanted backflow, back pressure or back siphonage of used water, and protect the drinking water system from contamination according to DIN EN 13959.
Check valves are mandatory in many countries around the world for products related to the supply of drinking water. Their other functions include the following:
With hot water applications in particular, material stability plays a key role. Neoperl offers check valves that are specially designed for high water temperatures.
The Injector AD is used to protect water supply systems. In contrast to other EN 1717 cat. 5 protection methods, it does not require electricity, pump or a water tank.
A NEOPERL check valve consists of a plastic housing, an external washer and a closure mechanism. The closure mechanism is fitted with a spring, a cone with washer, and a guide sleeve.
The strength of the spring is particularly important, as this has a significant influence on the opening pressure. The opening pressure is the pressure point at which the cone opens to allow a flow.
In the static state, the spring pushes the cone into its seat: the check valve is closed.
In the dynamic state, the water pressure is stronger than the spring. The cone is pushed out of its seat and allows the water through.
If the downstream pressure increases (backflow) or the upstream pressure decreases (back siphonage), the flow is reversed. The spring quickly extends in the check valve cone and closes the upstream side.