Abstract: An insert for use in a mandrel used in the production string of a well utilizing a gas lift operation is disclosed. The tubing unit and the valve lug forming the mandrel have communicating bores into which the insert, which is formed of an abrasion resistant material such as carbide, is placed. The insert is soldered in place, with the soldering to the valve lug being accomplished through a temporary opening in the valve lug. A method for assembly of the mandrel is described and an abrasion resistant sleeve for inclusion in a valve lug for use with a fluid operated valve is disclosed.

Abstract: A speed reducer construction for use with a drive motor which has a drive motor housing and a drive motor shaft which extends out of the housing comprises a reducer housing which is adapted to be coupled to the drive motor housing and encloses a portion of the motor drive shaft. The motor drive shaft is advantageously journalled in the reducer housing and it carries a worm made of a Nylatron material which is rotatable therewith. An output shaft extends transversely to the drive shaft and is journalled in the reducer housing and it carries a sleeve which is keyed thereto for rotation therewith. A gear is freely rotatable on the sleeve alongside a collar portion of the sleeve and is in meshing engagement with the worm. The drive of the motor through the worm to the gear and the output shaft is regulatable by a clutching device including a clutch spring which is biased against an end of the gear with a biasing force which is regulated by a torque adjusting wheel which is threaded on the sleeve.