Ennepetalsperre: Ruhrverband completes renovation of the ring piston valves

In March 2025, the Ruhrverband recommissioned the ring piston valve in the right bottom outlet of the Ennepetal Dam
after extensive refurbishment. With the help of the ring piston valves,
water volumes of up to 1,100 litres per second each can be released from the
Ennepetalsperre into the tailwater via the two bottom outlets. If the power station fails, both
sides are automatically put into operation so that there is always sufficient water available in the course of the Ennepe river
. After a good 20 years of operation, the time had come for a general overhaul of the
ring piston valves in both bottom outlets.

In July 2024, the right-hand ring piston valve was lifted out of its position using a crane and transported away by a specialist company for
overhaul. At the factory, the valve was completely dismantled,
cleaned and stripped of paint, including extensive documentation of the damage.
The valve was then re-preserved with a special coating that offers very high resistance
to abrasion forces and some wear parts were replaced. The measure has now been completed with the
reinstallation, again with the help of a mobile crane.

The left-hand ring piston valve had already been refurbished in the same way the previous year; here,
an aeration and venting valve installed behind the ring piston valve also had to be replaced because
its wear limit had been reached. The valve was reinstalled in April 2024. In total, the
Ruhrverband invested around 50,000 euros to make the components
that are important for the operation of the Ennepetal dam fit for the coming decades.