Overhaul at the Sorpe power plant - ball valve removed

This week, a ball valve was removed for inspection at the Ruhrverband's Sorpe power plant. The work was part of a planned maintenance measure to ensure the long-term operational safety of the power plant. 

A ball valve with nominal diameters of DN 1100 and DN 1200 from Escher Wyss is located upstream of the turbines and return pumps of the power plant. These valves date back to the construction of the Sorpe dam and were leaking in the meantime. They will therefore be removed one by one and overhauled by a specialised company. The first step was the ball valve upstream of pump 2. As the duration of the repair could not be precisely estimated in advance, this pipe was deliberately chosen - it could be closed with blind flanges after removal so that power plant operation could continue during the overhaul. 

The equalising pond was emptied in mid-October and the power plant was taken out of operation. During this time, water was released from the Sorpe dam via the bottom outlet. On Monday, 20 October, work began and the spherical valve weighing around seven tonnes was excavated. The next step was to install the blind flanges and refill the power plant pipeline. 

During the work, quagga mussels were also discovered in the pipeline. This invasive mussel species, which originates from the Black Sea region, has been spreading in German waters for several years and can clog pipes, filters and water technology systems due to its proliferation. The discovery confirms that the facilities at the Sorpe dam are also already affected by the further spread of the quagga mussel - a challenge that the Ruhrverband is currently having to face more and more at many of its dams and hydraulic structures.