Abstract: A connector assembly for connecting double walled insulated tubing uses connector members each having inner and outer walls engaging inner and outer walls of the tubing, and end walls which are configured to interengage and form a lapped joint, each outer wall and optionally each inner wall of each connector member being associated with a support ring so that each tubing wall is clamped between a connector wall and a support ring by blind rivets or other fastenings passed through the connector wall, the tubing wall and the support ring. The connector assembly can be either factory applied or applied in the field using available hand tools, yet provides a neat and reliable connection.