Fuel strainer

A fuel strainer (10) for a motor vehicle fuel system (76) having a fuel pump (82) mounted in a fuel tank (80) and a return conduit (78) for conducting surplus fuel back to the fuel tank. The strainer (10) includes a sealed bag made of a first porous membrane (12,14) having a first restriction to fluid flow thereacross, a partition inside the sealed bag made of a second porous membrane (18) having a second restriction to fluid flow thereacross less than the first restriction and dividing the sealed bag into a first fuel chamber (20) and a second fuel chamber (22), and a vapor orifice (36) across the first porous membrane between the first fuel chamber (20) and the fuel tank (80). The first fuel chamber (20) receives all of the surplus fuel from the return conduit (78). The second fuel chamber (22) is connected to an inlet (90) of the fuel pump (82) so that when the fuel pump is on, a low pressure zone in the second fuel chamber is separated from the first fuel chamber by the partition and from the fuel tank by the first porous membrane. The lower restriction to fluid flow thereacross exhibited by the partition relative to the first porous membrane permits surplus fuel to flow from the first fuel chamber into the second fuel chamber in preference to new bulk fuel from the fuel tank.