Izinto ezisetshenziselwa le valve yebhola yi-upvc, enokumelana nokugqwala okuqinile, ukumelana noketshezi oluphansi, namandla aphezulu.Isakhiwo sentambo yangaphakathi kulula ukuhlanganisa nokuhlakazeka.Indawo yokuvala yebhola nesihlalo ihlukaniswe phakathi, okungelula ukubangela ukuguguleka kokuvala uphawu lwe-valve.