The ornamental design for disinfection device for a valve, as shown and described.
FIG. 1 is a top perspective view of a disinfection device for a valve;
FIG. 2 is bottom plan view of the disinfection device for a valve as shown in FIG. 1;
FIG. 3 is a top plan view of the disinfection device for a valve as shown in FIG. 1;
FIG. 4 is a left side view of the disinfection device for a valve as shown in FIG. 1;
FIG. 5 is a right side view of the disinfection device for a valve as shown in FIG. 1; and,
FIG. 6 is a perspective view of the disinfection device for a valve as shown in FIG. 1 in use in the valve.
The broken lines represent portions of the disinfection device for a valve and environment in which the disinfection device is used and form no part of the claim.