scope:

This part of IEC 60609 serves as a basis for the formulation of guarantees applied to cavitation pitting for reaction hydraulic turbines, storage pumps and pump-turbines. It addresses the measurement and evaluation of the amount of cavitation pitting on certain specified machine components for given conditions, which are defined in the contract by output, specific hydraulic energy (E), speed, material, operation, etc. The cavitation-pitting evaluation is based on the loss of material during a given time and under accurately defined operating conditions. All wetted surfaces are considered. The contract documents shall state whether cavitation pitting on the hydraulic machine should or should not be anticipated in all or in some operating ranges. Guarantees that restrict the extent of cavitation pitting are necessary in the contract whether cavitation pitting is anticipated or not.