The dimensions for all types of shaft couplings and shaft runout tolerances for hydraulic turbines and generators are included in this standard. Shafts and couplings included in this standard are used for both horizontal and vertical connections between generators and turbines in hydroelectric installations.

This standard applies to the dimensions for all types of shaft couplings and shaft runout tolerances for hydraulic turbines and generators. Shafts and couplings included in this standard are used for both horizontal and vertical connections between generators and turbines in hydroelectric installations.

The 1987 standard applied only to integrally forged shafts. Present industry practice involves use of other types of shafts. This revision provides dimensions and tolerances for all types of shafts and couplings to assist in ensuring correct installation in hydroelectric applications.