In addition to electricity generation from fossil fuels, the share of solar and wind power in the grid is steadily increasing. In the future, flexible energy storage will therefore become increasingly important to compensate for weather-related fluctuations in the grid.

Pumped storage power plants support security of supply by storing potential energy in the form of water when there is a surplus of electricity and making it available again when needed. They have a higher and a lower reservoir. When electricity is needed, water from the upper lake flows through pipes into the lower lake and passes through a turbine, generating electrical energy. When there is excess energy, the water from the lower lake is pumped back into the upper lake.

For the smooth functioning of a pumped storage power plant, the water passes through a spherical valve before it hits the turbine. This spherical valve is usually only controlled when there is identical pressure upstream and downstream of the spherical valve. For the safe operation of the spherical valve, filtered water is required to control the sealing plate on the sealing seat in the closed position.

A manufacturer from Baden-Württemberg with several hydropower plants throughout Germany approached DANGO & DIENENTHAL with the following task.
Due to a previously used cast filter, the gate valve water was partially loaded with rust and other coarse particles. Since the metallic sealing surfaces of the spherical valve must be protected from any contamination, the previous cast filter was to be replaced.

DANGO & DIENENTHAL manufactured a filter system made of stainless steel with identical dimensions to the cast filter, so that replacement on site was possible without major modifications.

The advantage for the customer is that the filter has a longer service life due to the stainless steel material and also reliably protects the spherical valve from dirt particles.
The resulting reduction in maintenance intervals on the spherical valve means considerable better value for the customer.