This standard specifies the evaluation condition, measurement method and evaluation method of hydraulic turbine cavitation pitting, and also offers guaranteed amount of cavitation pitting.
This standard is applicable to the reaction hydraulic turbine whose single capacity is larger than 10 MW or whose mixed-flow runner nominal diameter is larger than or equal to 1m, and axial flow runner nominal diameter is larger than or equal to 2m. It also can be taken as reference for hydraulic turbine whose capacity or diameter is less than the aforesaid values.
For hydraulic turbine whose mixed-flow runner nominal diameter is larger than 6 m and axial flow runner nominal diameter is larger than 8m, its guaranteed amount of cavitation pitting can be determined separately by referring to this standard.
Hydraulic turbine may influence power, efficiency, vibration, and noise of assembling unit because of cavitation, and that situation doesn't belong to scope of this evaluation.
