Abstract: A check valve apparatus provides an overall valve body which can be placed in any typical flow line, a removable seat being provided at the inner portion of the valve body, the seat having a center orifice through which fluids can flow. The seat can be attached using a plurality of temporary tensile connectors, and the seat having a recess which receives a valving member therein. The valving member pivots in the seat and is weighted to a degree which aids in closure under static flow conditions. A closure spring can be added to further insure closure of the valve when desirable. In the preferred embodiment, the valving member pivots in the valve seat a distance less than ninety degrees, thus insuring valve closure during back flow conditions, the valving member projecting at least some degree into the line of flow of the fluid stream.