ʻO ka hoʻolālā impeller me ka impeller pani (maʻamau) a me ka impeller wehe e pili ana i ka hopu (ZGPO).ʻO ka hoʻokō maikaʻi loa me nā kūlana hana like ʻole, pani impeller me nā kiʻekiʻe efficiencies, haʻahaʻa NPSHr waiwai wehe impeller no nā wai kinoea loa, kiʻekiʻe paʻa paʻa (a hiki i 10%), nā paila me ka NPSHr haʻahaʻa loa.