A check valve comprises a valve housing defining a valve opening and a pair of posts arranged on opposed sides of the valve opening. A hinge pin is mounted between the posts. A pair of flapper elements are pivotally mounted to the hinge pin for rotation between a closed position in which they close the valve opening to prevent fluid flow through the opening, and an open position in which they permit fluid flow through the opening. The check valve further comprises a unitary element having at least one washer portion received on the hinge pin and at least one stop portion for forming a stop for engaging the flapper elements in their open position.