Abstract: An oil or gas well flapper-type safety valve is joined in the tubing string and has a cylindrical valve body with a valve seat therein. A flapper valve is hingedly supported from the valve body for movement between a closed position wherein the valve is seated against the seat and an open position wherein the valve is pivoted from the seated position. A control link is attached to the flapper valve at a point removed from the hinge. Control structure is provided for applying a force to the valve through the control link to selectively pivot the valve between its closed and open position. The control structure includes an hydraulically operated piston moveable in a valve control cylinder. The piston is attached to one end of the control link and is biased by a compression spring toward the valve to seat the valve.