Valves in action -
Bleeding and venting valve EB 3.51
Treatment of river water in a waterworks facility
Many waterworks use unaffected groundwater for the production of drinking water. Groundwater forms from precipitation that leaches into the soil. However, in densely populated areas the groundwater reservoir may not suffice to supply drinking water to a certain region. In such a case, river water is processed.
One of Germany’s major drinking water suppliers maintains a waterworks facility with fine filters for the transregional supply. It withdraws and treats water of the river Ruhr and supplies it to totally 20 districts in the surrounding areas with an annual output of 22 million cubic metres. The raw water from the river is contaminated by sewages, polluted air or agricultural residues and passes through different technical treatment stages to eliminate organic trace substances.
In the treatment plant the raw water is mixed with ozone and flows through three reaction tanks connected in parallel, in which the ozone reacts with the oxidizable substances. The water is subsequently conducted through a quick filter step and flows through an activated carbon adsorption step consisting of four filter tanks arranged in parallel. Finally, the drinking water is disinfected with ultraviolet light.
Various Mankenberg valves have been installed in the treatment plant and fulfill the task of bleeding and venting or vacuum breaking. The float-controlled start-up bleeding valve EB 3.51 ensures the air discharge from the supply lines during the filling process. The valve is soft-seated. Owing to its large seat diameter it can discharge large air volumes also at low pressures. The EB 3.51 has completely been made of deep-drawn stainless steel parts with excellent corrosion resistance, for example when in contact with ozone. The valve closes reliably, requires low maintenance and thus makes an important contribution to safety in the customer’s plant.
