I claim the ornamental design for a valve device, as shown and described.
FIG. 1 is a front view of a valve device;
FIG. 2 is a rear view thereof;
FIG. 3 is left side view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a top view thereof;
FIG. 6 is a bottom view thereof; and,
FIG. 7 is a perspective view thereof.
The ornamental design which is claimed is shown in solid lines in the drawings. The broken lines shown in the figures are for the purpose of illustrating portions of the valve device and form no part of the claimed design.