A valve includes a housing having an inlet and an outlet. A spool is fixed within the housing and defines a flow window therethrough for fluid communication between the inlet and the outlet. A piston is slidingly engaged in a piston compartment of the spool. A sleeve is slidingly engaged with the spool on an outer surface of the spool. The piston and sleeve are operatively connected for common motion along a sliding axis relative to the spool and housing between a first position in which the sleeve occludes the flow window to inhibit flow from the inlet to the outlet, and a second position in which the sleeve unoccludes the flow window to allow flow from the inlet to the outlet.