Parahi Piu Taki takirerehe mea hanga mai i te parahi hangai, e kiia ana ko te kore-return valve, i hangaia hei whakahaere i te rerenga whakamuri o te punaha whakahaere wai, ka tukuna te wai e te movable disc me te rere ki tetahi huarahi, e whakamahia nuitia ana mo te paipa, te papu, me te paipa.