Abstract: A bidirectional flow control valve has one port co-axial with a tubular spool and another port opening to the side of the spool, with openings formed in the sidewall of the spool to establish communication between the two ports. The end of the spool adjacent to the one port abuts the brim of a tubular hat-shaped insert which extends inside the lumen of the spool to a closed end on the distal side of the other port. Openings are formed in the sidewall of the insert which are in communication with openings in the sidewall of the spool via an annular groove in the exterior of the insert. The insert reacts against flow forces, helps equalize pressures from one end of the spool to the other, and does not increase the pressure drop across the valve.

Abstract: The magnetic interface between the housing and armature of a poppet type electromagnetically actuated fluid control valve creates a magnetic flux path through opposing axially and radially facing surfaces of the housing and armature to reduce the pull-in voltage of the valve at large axial gaps between the armature and housing.