Ko te kowiri tira whakahekeheke i te kokoru o te papu centrifugal ka whakauruhia ki te papa o runga. Heoi, ka hono tika te whakatiki kowiri tira ki te tuke piko whakarunga, ka taea te kowhiri i te whakaurunga papa o raro.
Ko te take i whakauruhia ai te kowiri tira whakahekeheke ki runga ko te aukati i te hau mai i te kohi i roto i te whakaheke rereke ka uru ki roto i te papu porohita, ka pakaru te cavitation ki te papu.