Patent ID: 8118054

Claim:
A valve comprising: a mounting body having a fluid inlet and a fluid outlet; a core tube adjacent to the mounting body, the core tube having an interior chamber with a proximal end and a distal end; a core slidingly disposed within the core tube interior chamber, the core having a proximal end, a distal end and a center located between the proximal end and the distal end, the core movable between an open position and a closed position relative to the mounting body, wherein the core distal end engages at least one of the mounting body fluid inlet and mounting body fluid outlet to block fluid flow therethrough when the core is in the closed position; at least one biasing member operable to bias the core in at least one of the open and closed positions; a coil disposed about the core tube, the coil operable to cause the core to move between the open position and the closed position when energized; a yoke encasingly disposed about the coil, the yoke having an opening adjacent to the core tube, the opening having a center, wherein a distance between the core center and the yoke opening center decreases when the coil is energized, wherein the yoke comprises a bottom tubular yoke hub and a top tubular yoke hub; a second biasing member positioned at one of the proximal end or the distal end of the core opposite the at least one biasing member, the second biasing member having a spring constant less than a spring constant of the at least one biasing member when the coil is not energized; wherein switching the valve from one of a normally-closed valve and a normally-opened valve to the other of the normally-closed valve and the normally-opened valve comprises swapping the at least one biasing member with the second biasing member and vice versa, and swapping the bottom tubular yoke hub with the top tubular yoke hub and vice versa.