Ivalve sisiqalelo solawulo olungachanekanga.Xa udlula ivalve, indawo yokusebenza inokuqukuqela kuphela kwicala elinikiweyo.Isebenza, xa ulwalathiso loxinzelelo oluphakathi lutshintsha.Ivalve isebenza ukumisa ukubuya kwe-meduim kwinkqubo.Ke ngoko, imveliso ikwabizwa ngokuba yivalve engabuyiyo.