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.