The ornamental design for an intensifiercylinder, as shown and described.
FIG. 1 is a front left top perspective view of an intensifier cylinder showing our new design;
FIG. 2 is a front elevation view thereof; and,
FIG. 3 is a left side elevation view thereof.
The rear elevation view is the same as the front elevation view shown in FIG. 2, and the top plan, bottom plan, and right side elevation views are each the same as the left side elevation view shown in FIG. 3.