IEC 60609-2:1997 pdf download – Cavitation pitting evaluation in hydraulic turbines, storage pumpsand pump-turbines- Part 2: Evaluation in Pelton turbines

IEC 60609-2:1997 pdf download – Cavitation pitting evaluation in hydraulic turbines, storage pumpsand pump-turbines- Part 2: Evaluation in Pelton turbines.
This part of IEC 60609 serves as a basis 101 the formulation of guarantees on cavitation pitting on Pellon turbine runners and also for the measurement and evaluation of the amount of cavitation pitting on Pelton turbine runners of a given turbine, which is defined in the contract by power, specific hydraulic energy ol machine (head). rotational speed, material, operation. etc.
The sequence of clauses in this part of IEC 60609 Is the same as in IEC 60609 (1978). The clauses on measurements and evaluation of the amount of cavitation pitting are practically identical to those of IEC 60609- Evaluation has to be based on the loss of material during a given time and under accurately defined operating conditions.
Guarantees which restrict the extent of cavitation pitting and drop erosion on Pelton turbines at the end of an operating period specified in the contract are necessary when cavitation pitting is expected in all or in some operating ranges. Such guarantees should include limits for operation wtiich are consistent with specified operating conditions,
1.2 Excluded topics
It is assumed In this part of IEC 60609 that the water is not chemically aggressive to a significant degree and that it is essentially free from abrasive solids.
The cavitation guarantee shall, however, be given on the basis of an agreed water analysis. If it becomes apparent In Ihe course of later analysis that the water is in fact more aggressive than the agreed analysis indicated, this shall be taken into consideration when judging whether the given guarantees have been met.
In case of a distorted inflow condition at the inlet of Ihe turbine due to irregularities upstream of the turbine, hydraulic effects may be raised, which beyond the Influence on hydraulic performance also may cause cavitation pitting. Therefore it is claimed for the basis of cavitation pitting guarantees that a satisfactorily uniform and vortex-free flow condition shall be provided. In case of damage. the influence of improper inflow condition shall be taken into account.
Abrasion due to water contaminated with solids (e.g. sand) cannot be considered as cavitation pitting. The solids content of the water and also — if relevant — the type of minerals and size and form of solid (sand) particles shall be stated In the water analysis and, if it reaches significant proportion, shall be the subject of a special agreement. Aspects of abrasive wear by sand erosion are dealt with in IEC 61366 (annex H).
Abrasion may cause a change of the geometry of the needle and/or the bucket and subsequently cavitation pitting as secondary damage. Such damage shall be excluded from the evaluation of cavitation.
This part of IEC 60609 serves as a basis 101 the formulation of guarantees on cavitation pitting on Pellon turbine runners and also for the measurement and evaluation of the amount of cavitation pitting on Pelton turbine runners of a given turbine, which is defined in the contract by power, specific hydraulic energy ol machine (head). rotational speed, material, operation. etc.
The sequence of clauses in this part of IEC 60609 Is the same as in IEC 60609 (1978). The clauses on measurements and evaluation of the amount of cavitation pitting are practically identical to those of IEC 60609- Evaluation has to be based on the loss of material during a given time and under accurately defined operating conditions.
Guarantees which restrict the extent of cavitation pitting and drop erosion on Pelton turbines at the end of an operating period specified in the contract are necessary when cavitation pitting is expected in all or in some operating ranges. Such guarantees should include limits for operation wtiich are consistent with specified operating conditions,
1.2 Excluded topics
It is assumed In this part of IEC 60609 that the water is not chemically aggressive to a significant degree and that it is essentially free from abrasive solids.
The cavitation guarantee shall, however, be given on the basis of an agreed water analysis. If it becomes apparent In Ihe course of later analysis that the water is in fact more aggressive than the agreed analysis indicated, this shall be taken into consideration when judging whether the given guarantees have been met.
In case of a distorted inflow condition at the inlet of Ihe turbine due to irregularities upstream of the turbine, hydraulic effects may be raised, which beyond the Influence on hydraulic performance also may cause cavitation pitting. Therefore it is claimed for the basis of cavitation pitting guarantees that a satisfactorily uniform and vortex-free flow condition shall be provided. In case of damage. the influence of improper inflow condition shall be taken into account.
Abrasion due to water contaminated with solids (e.g. sand) cannot be considered as cavitation pitting. The solids content of the water and also — if relevant — the type of minerals and size and form of solid (sand) particles shall be stated In the water analysis and, if it reaches significant proportion, shall be the subject of a special agreement. Aspects of abrasive wear by sand erosion are dealt with in IEC 61366 (annex H).
Abrasion may cause a change of the geometry of the needle and/or the bucket and subsequently cavitation pitting as secondary damage. Such damage shall be excluded from the evaluation of cavitation.