In February 2026, the following tests were performed at PSHP Ružín (Slovakia):

• Guarantee measurement at unit TG1.
• Efficiency measurement at unit TG2 before renovation.
• Guarantee measurement of butterfly valves at penstocks in front of TG1 and TG2.

The efficiency measurements were carried out in turbine as well as pump modes. The Gibson method was applied as a primary method for flow measurement. In addition to efficiency, other parameters such as pressure pulsations, cavitation emission, and vibrations (in cooperation with the operator´s vibro-diagnostic group). The pressure losses at pairs of the butterfly valves in front of both units were evaluated.

The measurements’ results can be briefly summarized as follows:

• Guarantee measurement at unit TG1 confirmed the fulfilment of required efficiency values at turbine as well as pump mode. Operation of refurbished unit does not require an aeration of draft tube.
• The results of the measurement at unit TG2 will serve the PSPP operator as a one of the bases for the planned unit refurbishment.
• Pressure losses coefficients of butterfly valves at both units are lower than guaranteed values.