I claim the ornamental design for a piping enclosure unit of an aquarium, as shown and described.
FIG. 1 is a front perspective view of a piping enclosure unit of an aquarium, showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof; and,
FIG. 7 is a front perspective view thereof shown in an environment of an aquarium and cabinet.
The bottom plan view of the design is not shown. The bottom is flat and not visible in use.
The dashed lines indicate unclaimed elements or the environment only and form no part of the claimed design.
The piping enclosure unit of an aquarium is shown with a symbolic break in its height. The appearance of any portion of the article between the break lines forms no part of the claimed design.