Pipe pig with running gear

US4677865A · kind A · utility

Assignee

• Mannesmann AG · DE

Inventor

• Peter Lehmann · Oebisfelde, DE

Key dates

• Filing date: Apr 24, 1985
• Grant date: Jul 7, 1987
• Expiry date: Apr 24, 2005

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B08B9/049
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A pipe pig for traveling through a pipe line is supported on and moved by two or three runners, which also can move circumferentially on the inside of the pipe to alter the angular position of the runners with respect to the longitudinal axis of the pipe. In this way the runners, which support the pipe pig by contact with the inside surface of the pipe, may rotate so as to avoid obstructions as they are encountered. Such obstructions may take the forms of openings in the pipe wall or protrusions into the pipe from the pipe wall. Various devices may be used to detect the presence of such obstacles and to detect both the axial position and angular orientation of the pig within the pipe. The apparatus for changing the angular position of the runners may be integrated with or separate from the apparatus for moving the pig axially in the pipe.