Abstract: The present invention relates to a reverse-flow prevention device for a fuel tank of an automobile which is provided between a filler port and the fuel tank in the automobile. The reverse-flow prevention device of the invention comprises a valve body of which circular interior space is divided into three to six sector-shaped regions and which includes a support bar provided in alignment with the division lines, and three to six valve discs having configurations to be closely fitted in the sector-shaped regions of the valve body and rotating around the support bar. Bearings of the support bar for rotation of the valve discs are provided with rotation-restriction sections which control the valve discs to rotate within a range of not more than 90.degree. as well as in one direction.

Abstract: Even if a bellows is provided in the vicinity of a fuel check valve to be installed between a fuel filler port and a tank, the valve can be operated stably with a structure in which a valve body of the check valve comprises an annular main body section and a tubular extension section extending over the substantially whole length of the inner peripheral side of the bellows.

Abstract: A check valve apparatus for a fuel tank of an automobile or the like compries only two members, i.e., a valve plate made of synthetic resin which is integral with rotating rod members and a valve body made of synthetic resin and having an annular configuration which is integral with bearings or the valve plate. The check valve apparatus is simple in structure and easy to assemble. During operation after it has been assembled, it will not easily dislodge from a pipe, and when the operator intends to detach it from the pipe, it will be readily detached.