I claim the ornamental design for a connector for medical fluid lines, as shown and described.
FIG. 1 is a perspective view from above of the connector for medical fluid lines comprising the new design;
FIG. 2 is a perspective view from below thereof;
FIG. 3 is a left side elevation view thereof, with the right side elevation view being identical thereto;
FIG. 4 is a front elevation end view thereof, with the rear elevation view being identical thereto;
FIG. 5 is a top plan view thereof; and,
FIG. 6 is a bottom plan view thereof.
The broken line showing of connector for medical fluid lines is included for the purpose of illustrating portions of the “article” and forms no part of the claimed design.