A fluid pump construction having a pump body. A valve chamber formed in the pump body with the pump body having an annular valve seat projecting into the chamber and an annular rib means also projecting into the chamber and facing the annular valve seat. A flexible valve member is disposed in the chamber between the valve seat and the rib means in such a manner that the rib means causes the valve member to be biased against the valve seat to close the same as the rib means flexes and tends to hold the valve member in substantially a conical configuration that is adapted to engage the valve seat and be traversed by the plane of the valve seat.