Abstract: A dual plate check valve has flaps (6) mounted on one or more hinge pins (7). The ends of the hinge pins (7) are received in sockets in inserts (12), which inserts (12) are receivable in open-sided recesses (13) formed in the annular valve housing (1) and are held in place by a keeper (14) located in a generally radially outwardly extending slot (15) formed in that housing (1). Where a single hinge pin (7) is used in a vertical orientation to support both flaps (6), a cylindrical bearing member may be supported by a lower one of said inserts (12) to extend through a lower hinge lug (21) of the first flap and partially through a lower hinge lug (20) of the second flap, thereby to support the lower hinge lug of the second flap independently of the first flap.