The story began last year when we produced a giant ball valve DN 1400 with a weight of an incredible 26 000 kg for our important partner ČEZ. The large ball valve replaced the original valve and now works reliably in the water reservoir Hněvkovice, which supplies cooling water to the Temelín nuclear power plant.

But what happened to the original ball valve?

In Hněvkovice are 4 pipelines of diameter DN 1400, which alternately supply cooling water to the nuclear power plant. With our delivery of a new ball valve DN 1400, ČEZ has started a complete renovation and overhaul of all ball valves that control and regulate the water supply. During the shutdown, the original ball valve is dismantled and a new or overhauled ball valve is immediately installed instead.

After disassembly, the original ball valve is sent for overhaul. If it is that the old ball valve cannot be repaired, a new piece is produced. If repair is possible, the overhaul will begin. In the final, that means, that there is always one extra ball valve available.

Entrance inspection and successful overhaul

And here our story continues. The new ball valve is happily in place and the old one is headed for the overhaul. It arrived at ARMATURY Group in Dolní Benešov in recent months. The entrance examination revealed age and condition. Ball valve DN 1400, PN 25, born in 1990, the residence of the Hněvkovice, weight 27 tons.

Transported for repair, including mounting insert, weight 2.5 tons. The control of this valve is provided by a direct double-acting hydraulic cylinder, weighing 3 tons. Tightness is ensured by sliding seats with bronze sealing surfaces.

Due to the large weight of the ball valve, disassembly was carried out in the production hall with heavy cranes, subsequent repairs were made at overhaul halls of ARMATURY Group. The sealing surfaces of the inner ball also required repair.

The repaired ball valve then headed back to Hněvkovice, where it had previously spent its twenty years.

And what's next?

When circumstances allow, our repaired ball valve will be replaced in the future by another piece of the valve, which will again go to refurbishment. The price also testifies to the advantage of the repair. Depending on the complexity, extent, and damage, the price ranges from 40 to 60 percent of the price of a new valve. And it pays off!

For more information:

Alfred Siebert, head of services and repairing