The greater use of subsea systems in the development of oil and gas reserves has brought about an increased use of small diameter flowlines for the transportation of untreated well fluids. Corrosion Resistant Alloy (CRA) pipeline materials such as duplex stainless steel are often specified for severe service condition but the relatively high cost of their procurement and installation can have a major impact on the economic viability of the field development.

With these factors in mind, the author’s company has been developing an efficient pipeline installation method which uses the radial friction welding process for joining CRA pipes in the size range 6–12.75" o.d. The paper describes the development of an automated pipelay system for the installation ship Seaway Falcon, the welding process and results achieved for duplex and super duplex stainless steels.