Method of fabricating a double walled pipe elbow

US5189790A · kind A · utility

Assignee

• Benteler Aktiengesellschaft · US

Inventors

• Wolfgang Streubel · Detmold, DE
• Rainer Hansen · Paderborn, DE

Key dates

• Filing date: Jun 12, 1991
• Grant date: Mar 2, 1993
• Expiry date: Jun 12, 2011

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T29/49812
• WIPO field: Environmental technology
• WIPO sector: Chemistry

Abstract

A double walled pipe elbow with an intermediate space between an inner pipe and an outer pipe is formed by joining the ends of a straight inner pipe and a straight outer pipe. The two pipes are bent into a desired shape and then placed in a shaping recess in a shaping tool. Seal plugs are placed at the opposite ends of the pipe elbow. In the sealed condition, a pressurized medium is supplied through at least one end seal plug into the inner pipe and between the inner and the outer pipe for expanding the outer pipe into surface contact with the shaping recess.