Ivalve yebhabhathane, ekwaziwa ngokuba yivalve eneflap, yisivalo esilawulayo esinesakhiwo esilula, esinokusetyenziswa ekutshintsheni ulawulo lwephakathi kumbhobho woxinzelelo oluphantsi. Ivalve yebhabhathane ibhekisa kwivalve eyindawo yayo yokuvala (icwecwe levalve okanye ipleyiti yebhabhathane) iyidiski kwaye ijikeleza ivalufa ukuze ivuleke kwaye ivale.