Demand for large rings is caused by the development of nuclear power plants. For the construction of nuclear
reactors are large steel rings with diameters up to 10 meters necessary. The height of the ring can be up to 6 meters.
Production of rings with these dimensions allows you to modify the current design of a reactor vessel. A design with
a lower number of rings is better, because there are not so many welding operations [6].
Production of rings with these dimensions is not possible in a normal hydraulic forging press (Fig. 1) described in
[1, 2, 3]. The distance between columns of the press B1 must be greater than the diameter of the ring DK. Also
maximal distance between places for tools RMAX must be greater than diameter of the ring DK. And finally, the
length of ring LK must be less than length of forging table LST. For rings with diameter around 10 meters is there not
such a big press in the whole world. It would be possible to design a hydraulic press with this enormous size, but it
would cost a large amount of money