ʻO nā ʻano koho metallurgic like ʻole - e puhi i nā vanes ma hope a me mua (ma nā impellers paʻa) e hōʻemi i ka hoʻihoʻi ʻana i loko o ka pamu, a kōkua i ka pale ʻana i ka hoʻopaʻa ʻia ʻana o ka sila - nā koho koho o nā vanes pololei a semi-Francis paha (mai ka 2 a i ka 8 vanes ma kekahi mau nui) hāʻawi. nā koho hydraulic ākea i nā nui hoʻokahi.