The oramental design for a propane tank sleeve, as shown and described.
FIG. 1 is a side view of a propane tank sleeve showing my new design;
FIG. 2 is a top plan view of the propane tank sleeve illustrated in FIG. 1;
FIG. 3 is a plan view of the propane tank sleeve illustrated in FIG. 1; and,
FIG. 4 is a bottom plan view of the propane tank sleeve illustrated in FIG. 1.
The broken lines showing of the propane tank over which the sleeve of the subject invention is disposed and the artwork presented thereon are for illustrative purposes only and form no part of the claim.