I claim the ornamental design for a secondary double containment pipe, as shown and described.
FIG. 1 is a perspective view of a secondary double containment pipe;
FIG. 2 is a front view of the embodiment shown in FIG. 1;
FIG. 3 is a rear view of the embodiment shown in FIG. 1;
FIG. 4 is a first side view of the embodiment shown in FIG. 1;
FIG. 5 is a second side view of the embodiment shown in FIG. 1;
FIG. 6 is a top view of the embodiment shown in FIG. 1; and,
FIG. 7 is a bottom view of the embodiment shown in FIG. 1.
The broken lines shown in FIGS. 1 and 4-7 illustrates a symbolic break in the length of the article. The appearance of any portion of the article between the break lines forms no part of the claimed design.