A check valve is a safety valve which permits water to merely flow in one direction and prevents unwanted backflow of water in the opposite direction.
Check valves for faucets and installation systems
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HomeProductsBackflow prevention

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.


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

NEOPERL offers a wide variety of plug-in backflow preventers.
For general applications

Neoperl offers you a wide variety of insert check valves. Our unique portfolio covers a broad range of applications.

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Check valves solutions PR model
Check valves for high pressure loads

Neoperl offers special check valves for the use in touchless and thermostatic faucets for instance.

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WV check valve for water meters
For water meters

Our check valves for water meters ensure that the device measurements are correct and reliable.

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Check Valve HT (high temperature)
For high temperature applications

With high temperature applications in particular, material stability plays a key role. Neoperl offers check valves that are specially designed for hot water.

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Injector AD

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.

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Cross-section of a check valve with housing (1), external washer (2), and internal closure mechanism (3).
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?
Check valves working Principles: In static conditions
Static state: no flow

In the static state, the spring pushes the cone into its seat: the check valve is closed.

Check valves working Principles: In dynamic conditions
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.

Check valves working Principles: In backflow conditions
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 approvalsAll 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 (260.6° 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 | 1.56MB
We can produce solutions tailored to the housing geometry or flow rate. Ask us with pleasure!
Do you need support?

We would be pleased to help you select the right check valve and, if required, develop customized solutions for you.

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