Two of the more well-known turbine types that are currently used in a variety of hydropower plants are classified as Kaplan types and Francis types. Both of these turbine types have a number of different auxiliary appliances and devices that are necessary for the entire plant to work.
A spiral case is one such appliance, designed for Francis turbine types. It wraps around the periphery of the unit due to it being circular in a cross-sectional area. Levstal performed a variety of operations in the process of manufacturing this particular spiral case for the hydropower plant – roll-bending, welding, blanking, assembly, NDT controlling, as well as painting and delivery to the client in question.