An automatically adjusting control valve comprises a valve body; a valve seat within the valve body; a sealing disc adjacent the valve seat when the valve is closed and offset from the valve seat when the valve is open; an armature adjacent the sealing disc and operable to move the sealing disc linearly within the valve body; a biasing mechanism which biases the armature toward a first position; and an actuation stem configured to overcome the biasing mechanism and move the armature between the first position and a second position upon manual operation. The actuation stem may comprise a portion which engages the armature during movement between the first position and the second position The portion may be configured to deform to accommodate manufacturing tolerances of the valve.