A check valve comprising: a valve housing defining a valve opening and a web extending across the valve opening; first and second mounting posts (12, 14) provided on the valve housing on opposite sides of the opening and extending away from the opening, each mounting post (12, 14) having a transverse bore formed therein, the end of the transverse bore (16; 116; 216) remote from the valve opening being at least partially closed; a first hinge pin and a second hinge pin; a pair of flapper elements pivotably mounted to the first and second hinge pins (36, 38) for rotation between an open position in which they permit fluid flow through the opening and a closed position in which they prevent fluid flow through the opening; characterised in that the check valve further comprises: a central mounting post mounted to the web and extending away from the valve opening, the central mounting post having a first bore extending in a longitudinal direction and a second bore formed transversely therethrough, the second bore being aligned with the transverse bores (16; 116; 216) provided in the first and second mounting posts (12, 14); wherein the first hinge pin is mounted between the transverse bore (16; 116; 216) of the first mounting post and the second, transverse bore of the central mounting post; wherein the second hinge pin is mounted between the transverse bore (16; 116; 216) of the second mounting post and the second, transverse bore of the central mounting post; wherein a hinge pin retaining element is arranged between adjacent ends of the first and second hinge pins (12, 14) within the second, transverse bore of the central mounting post; and wherein a fastener is received in the longitudinal bore of the central mounting post for fastening the central mounting post to the web and maintaining the hinge pin retaining element between the adjacent ends of the first and second hinge pins (36, 38). a valve housing defining a valve opening and a web extending across the valve opening; first and second mounting posts (12, 14) provided on the valve housing on opposite sides of the opening and extending away from the opening, each mounting post (12, 14) having a transverse bore formed therein, the end of the transverse bore (16; 116; 216) remote from the valve opening being at least partially closed; a first hinge pin and a second hinge pin; a pair of flapper elements pivotably mounted to the first and second hinge pins (36, 38) for rotation between an open position in which they permit fluid flow through the opening and a closed position in which they prevent fluid flow through the opening; a central mounting post mounted to the web and extending away from the valve opening, the central mounting post having a first bore extending in a longitudinal direction and a second bore formed transversely therethrough, the second bore being aligned with the transverse bores (16; 116; 216) provided in the first and second mounting posts (12, 14); wherein the first hinge pin is mounted between the transverse bore (16; 116; 216) of the first mounting post and the second, transverse bore of the central mounting post; wherein the second hinge pin is mounted between the transverse bore (16; 116; 216) of the second mounting post and the second, transverse bore of the central mounting post; wherein a hinge pin retaining element is arranged between adjacent ends of the first and second hinge pins (12, 14) within the second, transverse bore of the central mounting post; and wherein a fastener is received in the longitudinal bore of the central mounting post for fastening the central mounting post to the web and maintaining the hinge pin retaining element between the adjacent ends of the first and second hinge pins (36, 38).