Fuel tank ventilation valve

摘要

The ventilation valve system, for a fuel tank, has a ball (2) of a precise dimension and shape in a housing (3) with angled side walls. After a pitch of a defined angle (2a,2b) of the vehicle, the residual weight closes a swing flap (4) with an elastomer seal (5), to prevent movement of the liquid fuel from the tank into the fuel vapour absorption recovery system. The ball and the housing are of a material which is dimensionally stable in the fuel, such as polyoxymethylene (POM). The ball and valve flap are of magnetic materials.