Automatic drain valve

FIG. 1 is a front view of an automatic drain valve in accordance with my new design;

FIG. 2 is a rear view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a perspective view thereof.

The portions of the automatic drain valve shown in coarse dot pattern and outlined in dashed lines form no part of the claimed design.