Techniques for joining lined pipelines

Abstract

A connector for lined pipelines includes a tube having opposed male interface elements extending inwardly from respective ends of the tube. One or more circumferential permeable chokes project radially from each male interface element. The chokes minimize flow of oxidizing fluid from the bore into the micro-annulus between the liner and the pipe while maximizing flow of fluid from the micro-annulus into the bore in the event of catastrophic pressure drop in the bore. To maintain gaps between the tube ends and the pipe liners for fluid flow, shoulder formations defined by radially-projecting bands extend circumferentially around the tube. The connector may be used in a joint arrangement where each liner includes a body section, an end section of lesser thickness and greater bore than the body section that terminates short of an end of the pipe, an inner step disposed between the body section and the end section, and an outer step disposed between the end section and the pipe.