Vapor storage canister with foam screen retainer

A fuel vapor storage canister having a screen assembly between a mass of carbon granules in the storage canister and a purge port of the storage canister. The fuel vapor storage canister includes a cup-shaped plastic body defining a carbon bed chamber and a plenum in the canister body covered by the screen assembly. The screen assembly includes a pair of concentric cylindrical bosses around the plenum, a plastic foam screen over the plenum seated on a circular edge of each of the concentric cylindrical bosses, and a retainer having a plurality of flexible barbs and flexible reinforcements resiliently biased against opposite sides of the outermost one of the cylindrical bosses. Concentric circular segments of the plastic foam screen are compressed tightly between an annular planar side of the retainer and each of the circular edges of the concentric cylindrical bosses to positively prevent migration of carbon granules around the foam screen. The barbs prevent dislodgment of the retainer from the outermost one of the cylindrical bosses. The reinforcements protect the integrity of the retention of the barbs by preventing creep of the outermost one of the cylindrical bosses attributable to the forces exerted thereon by the barbs.