Pad plunger assembly with interfitting keys and key ways on mandrel and pads

摘要

A pad plunger assembly includes an elongated mandrel having a pair of opposite ends, at least one pad subassembly disposed about the mandrel and extending between the opposite ends thereof, a plurality of annular key ways and annular keys respectively defined on the mandrel and the pad subassembly, the key ways and keys interfitting with one another so as to impede the ability of a fluid to flow along the mandrel beneath the pad subassembly and adjacent to the mandrel and from one to the other of the opposite ends of the mandrel, and elements for securing the pad subassembly on and around the mandrel.