The ornamental design for an expansionvalve, as shown and described.
FIG. 1 is a front perspective view of an expansion valve showing our new design;
FIG. 2 is a rear perspective view thereof;
FIG. 3 is a front elevational view thereof;
FIG. 4 is a rear elevational view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a left side elevational view thereof; and,
FIG. 7 is a right side elevational view thereof.
The broken lines shown in the figures are included for the purpose of illustrating portions of the expansion valve and form no part of the claimed design.