Process and apparatus for making heat recoverable composite couplings

摘要

Described herein is a process and apparatus for making a composite coupling useful in joining cylindrical substrates such as tubing. The composite coupling joins the cylindrical substrate by heat recovery of a component of a coupling over the substrate. The coupling manufacturing process comprises cooling a tubular heat-recoverable metallic compression sleeve to below a temperature at which the material undergoes a martensitic transformation, expanding the cooled metallic sleeve and inserting by means of a pilot rod a cooled tubular insert which will fit snugly and be concentrically disposed within the sleeve. The composite couplings so formed are advantaged over monolithic couplings which contain no insert by improved resistance to tensile stress, gas tight joints, and ease of manufacture.