WESER Stop valves

WESER Freistrom-Absperrventile

50 years of WESER valve - unrivalled progress.

Origin shipbuilding

Since 1930, the Kemper metal foundry in Olpe had made a name for itself as a manufacturer of castings for shipbuilding. Among other things, they produced ship's propellers from bronze that were corrosion-resistant even in aggressive seawater. With the expertise gained here, a range of corrosion-resistant ship valves was then developed in the 1960s, which was presented to the public at a trade fair in Hamburg. These special bronze valves and slides attracted the attention of the publich works service in Bremen. There, they had been struggling for some time with immense damage caused by dezincification corrosion to components of drinking water installations. "The conventional shut-off valves installed have to be replaced every two years," they said at the time.

WESER Absperrventile früher und heute

Reason for corrosion: Weser water quality

The reason for the problems in Bremen was the quality of the water, which was primarily obtained from the Weser. At that time, the river was still heavily polluted with industrial wastewater. To make its water drinkable, extensive treatment measures were necessary. These in turn made the drinking water corrosive to metals - the water became aggressive.

Origin of the WESER brand

The question was therefore raised as to whether KEMPER could not also produce a shut-off valve for drinking water installations from its corrosion-resistant alloy. After determining the investment costs and subsequent "careful consideration", the first "WESER" shut-off valves, made entirely of gunmetal, were produced in 1972 and successfully used in Bremen, among other places. The Weser, the source of the problem , thus became the eponym for a valve series that has now been successful for 50 years.

50 years of success story against aggressive water

To ensure drinking water quality, all water suppliers have to treat their "raw water" with different measures - depending on its origin and composition. In the process, the chemical, biological and physical parameters of the water change. As a result, the drinking water can become aggressive for metals and cause corrosion. Each adjustment of the treatment measures also changes the parameters of the drinking water - a reliable prediction of the corrosion potential of their drinking water over years is therefore hardly possible for the suppliers. This results in warranty risks for planners and contractors, which can be counteracted by using corrosion-resistant installation materials. The areas of application for KEMPER WESER valves have thus grown continuously over the past 50 years.

Progress through continuous development

In the course of its 50-year existence, the WESER series has been continuously expanded with innovative features. A 10-year warranty documents the extraordinarily high level of operational safety that has been achieved. 

  1. Particularly pressure and temperature resistant due to seat seal made of special EPDM
  2. Dezincification-free and corrosion-resistant gunmetal, according to the positive list of the German Federal Environment Agency and the European 4 Member States Initiative.
  3. With internal or external thread or with press-fit connections for various pipe systems
  4. Erosion-proof valve seat made of stainless steel
  5. freely mounted, rotatable cone prevents abrasion of the seat seal
  6. Drinking water-hygienic design prevents bacterial growth
  7. Permanent operational reliability due to maintenance-free EPDM spindle seal that can be replaced under full system pressure
  8. Permanently smooth running due to self-lubricating stem seal and actuating thread separated from the medium
  9. Low pressure losses due to flow-optimised design