Reference

WaStop DN700 Short with Bell Bolt Flange

The city of Münster in Hessen, Germany, faced a critical challenge with Lake Semme. A beaver had constructed a dam, obstructing the water flow and causing backflow into an NPS 32 outlet pipe that normally discharged water back into the lake. This backup pushed water 492ft upstream to the upper edge of a threshold at a nearby pumping station—just 16 inches from overflowing. If the water breached this threshold, the station would be forced to pump excess water to the sewage treatment plant, significantly increasing energy costs. Even more concerning, prolonged backflow threatened to flood a nearby industrial area, endangering buildings and businesses, which happened in the past.

A simple installation of a Wastop Inline check valve at the lake outlet wasn’t feasible, as water would simply bypass it by flowing into a nearby chamber a few meters downstream. A more strategic solution was required.

The solution

To effectively address the issue, we installed a special solution Wastop Inline check valve 164ft downstream in a narrow, one-meter-wide chamber. Since the pipeline was constantly submerged, a diver measured the exact inner diameter, as traditional access was impossible. Given the chamber’s tight dimensions, we custom-trimmed the Wastop to be even shorter than the standard short version. Additionally, we integrated the reinforcement ring, normally installed separately, directly into the unit to ensure a perfect fit within the confined space.

The choice of membrane was crucial for this application. We selected the soft S2 membrane, designed to open at just 7 inches of differential pressure. This allowed the valve to function underwater despite backpressure, effectively preventing water from cresting the pumping station’s threshold. By modifying the body, trimming the bottom, and utilizing the uniquely responsive S2 membrane, we provided the only solution on the market capable of operating under these conditions, opening even with backpressure at minimal differential pressure.

For installation, we sealed one end of the pipeline, pumped out the water, and carefully positioned the Wastop. This setup successfully prevented backflow at an early stage, protecting the industrial area while keeping energy costs in check, all despite the complex and restrictive environment.

  • Product

    WaStop® Inline Check valve

  • Area of ​​use

    Flood protection

    We are increasingly experiencing heavy rain and extreme weather. The good news is that there are ways of preventing and minimising the risk of flooding. Our patented check valves have prevented thousands of floods.

  • Area of ​​use

    Residential

    You should never have to come home to a basement that is under water, or have to put up with odours from your drainage pipes. We offer solutions that are specially adapted to stop backflow, prevent flooding, stop pests in the drains and ensure that unpleasant smells from the drains do not enter the home.

  • Area of ​​use

    Pests & Odors

    Pests can cause both damage and disease if they enter water and sewer systems. We offer simple and cost-effective solutions to prevent this. We also offer products that stop unpleasant smells from drains.

For more information

Share this post

FAQ

We have collected frequently asked questions and answers here.

Areas of application

Solutions for all contexts