METHOD AND APPARATUS FOR CONNECTING A TUBE TO A MACHINE

摘要

A connection (10) of a tube (12) to a machine (14) includes a plurality of rolled grooves (36) in a region of contact (32) between the collet (18) of a compression fitting (16) and the tube (12). The grooves (36) reduce the occurrence of fretting of the tube surface (28) while a region (38) of residual compressive stress formed in the tube (12) proximate the bottom of each groove (36) by the rolling process serves to counteract the stress concentration created by the grooves (36). In one embodiment a single groove (36) formed in a thread pattern extends from above collet (18) to within the area of contact (32).