US D493209 S1
FIG. 1 is a plan vew of a flap valve showing my new design;
FIG. 2 is a side elevation view thereof;
FIG. 3 is a vertical sectional view thereof;
FIG. 4 is a top perspective view of the flap valve with its flap in a closed position; and,
FIG. 5 is a bottom perspective view thereof.