Abstract: A ball valve is turned relative to its seat by means of three concentric sleeves mounted within a housing bore. Pins carried by the middle piston sleeve extend outward into slots in an outer carrier sleeve and inward into cam grooves in the outer wall of an inner drive sleeve. Axial movement of the middle sleeve under hydraulic pressure causes turning movement of the inner sleeve which then drives through bevel gears to turn the ball valve. The parts are constructed so that hydraulic forces within the housing acting to hold the ball valve in closed position against its seat are substantially balanced by forces in the opposite direction acting against the outer sleeve. A hold-open tube may be passed through the opening in the ball valve, to come to rest upon a choke sleeve.

Abstract: A ball valve is turned relative to its seat by means of three concentric sleeves mounted within a housing bore. Pins carried by the middle piston sleeve extend outward into slots in an outer carrier sleeve and inward into cam grooves in the outer wall of an inner drive sleeve. Axial movement of the middle sleeve under hydraulic pressure causes turning movement of the inner sleeve which then drives through bevel gears to turn the ball valve. The parts are constructed so that hydraulic forces within the housing acting to hold the ball valve in closed position against its seat are substantially balanced by forces in the opposite direction acting against the outer sleeve.

Abstract: A valve adapted for installation at the lower end of a drilling kelly for closing the bore of the kelly when adding a section of drill pipe so that the mud content of the kelly is not discharged onto the derrick floor; the valve also being adapted with minimum change in parts, to be inverted and installed at the upper end of the kelly to serve as a safety valve, providing blow out protection.