A valve assembly for a feeding or drinking vessel comprises a valve seat surface 230 and a valve element having a valve face 240 opposing the valve seat surface, a centre axis and a rim 234. The valve element further comprises a biasing element 242 configured such that, in a rest position, the valve face is biased against the valve seat surface. The valve element rim is arranged to be anchored and the biasing element is positioned between the valve element centre axis and rim. The biasing element may further comprise a folded section of a resilient diaphragm 204 that is configured to partially unroll when moved from the rest position.
