Calculation of stresses and safety factors in the neck of a bucket of a Pelton turbine

A discontinuity was found in one of the necks of a Pelton turbine during an inspection, which could affect its integrity as well as the operation of the hydropower plant. A process was carried out in order to remove the discontinuity. The geometry of the neck was modified and it was necessary to validate the operating conditions of the turbine. The stress state and the safety factors for static and fatigue conditions were calculated for the hydropower plant taking in account the geometry of the repaired neck.

The estimation of the stress state and the safety factors in the bucket neck brought to our customer the following benefits:

• Reliability and availability of a critical component for the hydropower plant operation
• Saving money and time in recovering of the bucket neck
• Knowledge of the turbine behavior under different scenarios of the hydropower plant operation
• Prediction of the turbine response under unusual events, which allows to carry out maintenance activities based on prediction and prevention