Isivimbeli sokubuyela emuva esisetshenziselwa ikakhulukazi ukuphakelwa kwamanzi ukusuka endaweni yasemadolobheni kuya endaweni evamile yokukhucululwa kwendle sikhawulela ngokuqinile umfutho wepayipi ukuze ukugeleza kwamanzi kube indlela eyodwa kuphela.Umsebenzi wayo ukuvimbela ukugeleza kwe-backflow medium yamapayipi noma yisiphi isimo sokugeleza kwe-siphon emuva, ukuze kugwenywe ukungcoliswa kokubuyela emuva.