Steam Turbine Blade Design Options: How To Specify Or Upgrade

This paper is intended to familiarize people, who are responsible for rotating equipment, with options in blade designs. The information is meant to be helpful in conjunction with blade specifications, design reviews, inspection and trou­ bleshooting. Mechanisms of causes of blade fatigue and strength de­ terioration are reviewed. With emphasis on these factors, geometrical and manufacturing differences of blade fastenings, lashings and shrouds are discussed and a qualitative method of identifying stress distributions and stress concentrations in root cross sections is presented. Graphs in tabular form coordinate the most common types of blade roots, appropriate critical root cross sections, shroud and damping designs in an order of increasing strength .