EXPANDER SYSTEM FOR STEPWISE EXPANSION OF A TUBULAR ELEMENT

摘要

An expander system for radially expanding a tubular element having an unexpanded portion of a first inner' diameter, the expander system including an expander movable between a radially retracted mode and a radially expande d mode, the expander being operable to expand the tubular element from said first inner diameter to a second inner diameter larger than the first inner diameter by movement of the expander from the radially retracted mode to the radially expanded mode thereof, wherein the expander comprises a contact section of a diameter larger than said first inner diameter when the expande r is in the radially retracted mode, and wherein said contact section is arranged to prevent axial movement of the expander through the unexpanded portion of the tubular element when the expander is in the radially retracte d mode.