The ornamental design for a pumpportion of a positive displacement pump assembly, as shown and described.
FIG. 1 is a front/right side isometric view of an embodiment of a pump portion of a positive displacement pump assembly (the ghosted lines form no part of the claimed design);
FIG. 2 is a front elevational view of the pump section of FIG. 1 (the ghosted lines form no part of the claimed design);
FIG. 3 is a rear elevational view of the pump section of FIG. 1 (the ghosted lines form no part of the claimed design);
FIG. 4 is a right side elevational view of the pump section of FIG. 1 (the ghosted lines form no part of the claimed design);
FIG. 5 is a left side elevational view of the pump section of FIG. 1 (the ghosted lines form no part of the claimed design);
FIG. 6 is a top view of the pump section of FIG. 1 (the ghosted lines form no part of the claimed design); and,
FIG. 7 is a bottom view of the pump section of FIG. 1(the ghosted lines form no part of the claimed design).