The ornamental design for a pipefitting, as shown and described.
FIG. 1 is a perspective view of the pipe fitting;
FIG. 2 is a bottom perspective view of the pipe fitting;
FIG. 3 is a front view of the pipe fitting;
FIG. 4 is a rear view of the pipe fitting;
FIG. 5 is a right side view of the pipe fitting;
FIG. 6 is a left side view of the pipe fitting;
FIG. 7 is a top view of the pipe fitting; and,
FIG. 8 is a bottom view of the pipe fitting.
The broken lines showing in the figures are included for the purpose of illustrating portions of the pipe fitting that form no part of the claimed design.