The ornamental design for a reciprocatingpump, as shown and described.
FIG. 1 is a top perspective view of a reciprocating pump showing my new design.
FIG. 2 is a bottom perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a top plan view thereof;
FIG. 6 is a bottom plan view thereof;
FIG. 7 is a right side view thereof; and,
FIG. 8 is a left side view thereof.
The broken line showing of the reciprocating pump is included for the purpose of illustrating portions of the reciprocating pump and forms no part of the claimed design.