The ornamental design for a flowcontrolvalve, as shown and described.
FIG. 1 is a top, front and left-side perspective view of a flow control valve showing our new design;
FIG. 2 is a bottom, rear and left-side 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 left side view thereof; and,
FIG. 8 is a right side view thereof.
The broken lines shown in the figures are included for the purpose of illustrating portions of the flow control valve and form no part of the claimed design.