The ornamental design for a pumpassembly, as shown and described.
FIG. 1 is a front perspective view of a pump assembly showing our new design;
FIG. 2 is a front elevational view;
FIG. 3 is a back elevational view;
FIG. 4 is a right side elevational view;
FIG. 5 is a left side elevational view;
FIG. 6 is a top plan view; and,
FIG. 7 is a bottom plan view.
The broken line showing of the two apertures and the elements contained therein in FIG. 6, the four square elements and inner ring in FIG. 7 and the partial showing of the elements inside the cylindrical chamber in FIG. 1 is for illustrative purposes only and forms no part of the claimed design.