FIG. 1 is a front view of a flush valve cover showing our new design, the broken line showing of the flush valve body is for illustrative purposes only and forms no part of the claimed design;

FIG. 2 is a left side view of our new flush valve cover design, the right side view being a mirror image thereof;

FIG. 3 is a top view of our new flush valve cover design;

FIG. 4 is a rear view of our new flush valve cover design;

FIG. 5 is a bottom view of our new flush valve cover design;

FIG. 6 is a front elevational view of a second embodiment showing our new design, the broken line showing of the flush valve body is for illustrative purposes only and forms no part of the claimed design;

FIG. 7 is a rear view of the new flush valve cover design of the embodiment of FIG. 6;

FIG. 8 is a left side view of the new flush valve cover design of the embodiment of FIG. 6;

FIG. 9 is a right side view of the new flush valve cover design of the embodiment of FIG. 6;

FIG. 10 is a top view of the new flush valve cover design of the embodiment of FIG. 6; and,

FIG. 11 is a bottom view of the new flush valve cover design of the embodiment of FIG. 6.