Abstract: A dual plate check valve comprises a substantially cylindrical valve body 10 provided with a diametrical cross-member 14 thereby defining a pair of substantially D-shaped apertures, and two substantially D-shaped plates 18, pivotally connected by a hinge means 20 parallel to said cross-member 14, and pivotable between a valve open position and a valve closed position in which the sealing face of each plate engages a sealing face provided on a valve seat 16 which surrounds each aperture. A groove is provided in each sealing face which is then filled with a weld inlay 40, 42 and then machined to provide a sealing face portion of a more durable metal alloy.