Abstract: The improved shaft locking apparatus includes a body with a bore therethrough and includes balls mounted in radial ports in said body so that in one position the balls partially extend into the bore and in restricting the bore lock a shaft associated with the apparatus from axial movement. A heat sensitive material is used as a part of the balls supporting means and when it is subjected to excessive heat, heat above its design limitations, its support of the balls relaxes and allows their retraction from the bore to thereby allow axial movement of the shaft.

Abstract: The improved choke includes a body with an internal valve chamber, an inlet and an outlet communicating through the body into the valve chamber, a valve seat surrounding the opening of the outlet into the valve chamber, and a valve member mounted within said body to move toward and away from said valve seat to control flow therethrough, means for moving the valve member in said body, the valve member having a stem and a replaceable, wear-resistant tip which is provided with a sleeve insert secured within the stem opening and having internal threads which mate with external threads on the end of the stem, the tip recess includes a groove into which a portion of the sleeve insert is swaged to secure it tightly into the tip.

Abstract: An improved pressure transmitter having a body with signal pressure responsive means and output pressure means having pressure responsive means, a supply of fluid pressure to said output pressure means, and adjusting means interposed between said signal pressure responsive means and said output pressure responsive means to adjust the force transmitted between said two pressure responsive means.

Abstract: Flow control apparatus is disclosed in which a closure element is reciprocated between flow controlling positions by means of a stem which is substantially counterbalanced with respect to forces on the stem due to the pressure of the fluid being controlled as well as ambient pressure conditions.

Abstract: A choke suitable for use in the wellhead of a production well including a body having an inlet, an outlet and a seat, a valve member or gate adapted to move relative to said seat to restrict flow therethrough, a pressure responsive operator connected to move the gate with respect to the seat, a manual operator connected to said pressure responsive operator, means releasably connecting said manual operator to said gate to manually move said gate and for releasing said manual operator from said gate to allou said pressure responsive operator to move said gate and a control on the exterior of said manual operator connected to said releasable connecting means.

Abstract: An apparatus for indicating at the surface, the subsea well head pressure including; a reservoir, a subsea hydraulic transmitter, a pump to pump hydraulic fluid from reservoir to the subsea hydraulic transmitter, a pressure gauge connected at the surface in the line from the pump to the transmitter, means connecting the transmitter to said reservoir, means for connecting the transmitter to the well head whereby well head pressure is delivered to the transmitter, the transmitter being located on the subsea well head equipment, a flow controlling restrictor connected between the pump and the pressure gauge and the transmitter, the transmitter having a body with a bore at one end and a counterbore at the other end, a piston slidable in said bore and connected to a diaphragm in the counterbore, the piston being exposed to well head pressure, the diaphragm being exposed to pump pressure on one side and to hydrostatic head on the other side with opposite sides of the diaphragm having equal areas to compensate for h