A steam turbomachine valve includes a valve body having an inlet portion, an outlet portion, and an interior portion. The interior portion includes an inner wall. A valve member is slidingly disposed within the interior portion of the valve body. The valve member includes an outer surface. A seal element is mounted to, and extends about, the outer surface of the valve member. The seal element is spaced from the inner wall by a gap. A seal assembly is mounted to the inner wall. The seal assembly spans the gap and is configured and disposed to contact the seal element of the valve member.