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Neoperl's backflow preventers protect drinking water pipes from the unwanted backflow of used water. A precise closing mechanism prevents contaminated water from flowing back into the pipework.
Applications
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:
- They protect sensitive devices from being damaged by the backflow of wastewater.
- They prevent pipework from running empty or dry, prevent the associated damage, and facilitate restarting.
- They prevent cross-over flow in systems with different line pressures.
- They ensure correct operation in complex systems by ensuring the direction of flow.
- They protect pressure-sensitive systems whenever the system pressure fluctuates.
Our range
For high-tech applications
With high tech applications in particular, material stability plays a key role. Neoperl offers check valves that are characterised by its resistance against hot water and certain chemical compositions.
For protection by air gap
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.
What does a check valve consist of?
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.
How does a check valve work?
Static state: no flow
In the static state, the spring pushes the cone into its seat: the check valve is closed.
Dynamic state: flow
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.
Backflow: flow in reverse direction
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.
Materials and approvals
- All NEOPERL check valves are made from POM. This plastic is particularly suitable for continuous operation at 65 °C (149° F) and for short periods of time at 90 °C (194° F).
- Check valves for use at high temperatures are made from NORYL plastic – a material that can withstand a constant temperature of 127 °C (260° F).
- Our standard materials for seals in the drinking water sector are EPDM, silicone and NBR.
- NEOPERL check valves meet all the relevant hygiene and mechanical approvals for use in drinking water and have been tested to DIN EN 13959.
Flow rate ranges
In this PDF file, you can see which of our product lines cover which range of flow rates.
Check Valves: flow rate range by product line | pdf | 742.42KB
