A key measure to promote sustainability is the responsible use of resources, especially in industrial plants. The choice of materials for components such as valves leaves only limited room for discussion. It is determined by the area of application of the valve, the ambient conditions, the type of fluid and the system layout.
However, if valves are manufactured from deep-drawn sheet metal, this enables significantly lower material consumption compared to cast or solid material. In addition, this type of production produces very little CO2. With regular maintenance and, if necessary, a cost-effective repair or general overhaul, these valves impress as long-lasting system components.
The operators of a waterworks in Saarland were also convinced of this. Two diaphragm-controlled overflow valves from Mankenberg are installed in the plant, which are used as drain valves for the sedimentation tank. As underwater valves, they operate in a highly corrosive atmosphere and should first be assessed with regard to the cost-effectiveness of the planned repair work before being repaired.
The valves were very dirty and rusted, the guide surfaces on the piston, the piston guide and the spindle were scratched. In addition, the housing sealing surfaces to the spring cover were pitted. However, the calculated costs for the repair remained manageable and the operator agreed to the proposed repair.
Fittings like new
Many valve components could be reused with little effort. They were cleaned or sandblasted and the housing sealing surfaces and valve seat were polished. Wear parts such as seals and diaphragms, which are available as a maintenance kit from Mankenberg, were replaced.
Once the cleaned components and replacement parts had been fitted, the two overflow valves were subjected to a leak and function test. The labelling was then updated and the valves travelled back to their home in Saarland.
After a successful repair, the valves are no longer recognisable under water after ten years of use. They look practically new and are ready to do their job for another ten years without any problems. The waterworks operator invested just one seventh of the original purchase price to carry out the resource-saving repair of its valves. Thanks to single-origin production, the replaced components are fed into the recycling cycle - a small but significant contribution to promoting sustainability.
