The company’s hyper-duplex SAF 3207 HD tubing is the latest addition to the duplex family of stainless steels and is a candidate for deep umbilicals — the electrical and hydraulic system “lifelines” which link remote subsea wellheads to processing platforms. It was developed to meet demands for more remote and deeper subsea umbilicals and other tubing applications that see extreme depths, temperatures, and pressures.
Compared its predecessor, Super-duplex SAF 2507 — the established workhorse of the oil and gas industry — hyper-duplex SAF 3207 HD has better yield strength and fatigue properties as well as greater resistance to crevice corrosion. It has a tensile strength of 980 to 1,180 MPa and maximum operating temperature up to 90°C (194°F) compared to 800 to 1,100 MPa and 65°C (150°F), respectively for super duplex. The higher yield strength of the hyper-duplex alloy withstands greater pressures, lets umbilicals be thinner, and lowers installation costs. Use of the new grade makes it possible to develop installations and explore new fields previously thought to be too expensive and technologically unattainable.
Stainless steel umbilical tubing from Sandvik is available from 11 to 89 mm outside diameter. Further details are available via the Sandvik Materials Technology Web site.
Sandvik’s Hyper-duplex SAF 3207 HD stainless was specifically designed for deep water, high temperature and extreme pressure applications. It has good weldability for welding procedures similar to those used Super-duplex SAF 2507. Welded joints are tough, strong, and resist corrosion.