a locking assembly for well devices , such as a cable suspended electric pump , for anchoring the device against both axial and rotative movement within a well flow conductor . the assembly includes locking keys engageable with locking recesses provided in the flow conductor to support the device within said conductor . an expander mandrel actuated by the torque forces developed by a rotating element of the well device coacts with said locking keys to urge said keys into tighter locking position and thereby prevent rotation of said assembly within the flow conductor . the assembly also includes an equalizing valve which equalizes pressures across the assembly and the well device prior to releasing the locking action of the locking keys .