A fuel supply unit includes a fuel reservoir (22) for holding fuel. A fuel pump (18) is in the reservoir for pumping fuel from the reservoir. A jet pump assembly (16) is within the reservoir for drawing fuel from a fuel tank into the reservoir. A seal structure (24) has a flange (28) with a living hinge (31). The seal structure is operatively coupled with a housing of the jet pump assembly and disposed between the housing and a portion of the reservoir, with a portion of the flange being pivoted about the living hinge such that the portion of the flange engages an interior surface of the reservoir, providing a seal between the housing of the jet pump assembly and the interior surface of the reservoir.