Trelleborg Offshore has completed design, manufacturing and testing of the world’s largest bend stiffener. To facilitate the fabrication, an additional polyurethane (PU) dispensing machine was specially commissioned at Trelleborg Offshore’s plant in Skelmersdale, England.
The bend stiffener was specifically developed for use by StatoilHydro, who are responsible for the development and operation of the Vega field in the North Sea and produced for Aker Solutions. Typically a bend stiffener is around 1,000 kilograms/ 2,204 pounds in weight and up to five meters/ 16 feet in length. The record-breaking bend stiffener was over twice the length and around five times the weight in PU.
Trelleborg Offshore produces custom-designed integral bending stiffeners for rigid riser end fittings. These conically shaped polyurethane moldings are used in offshore oil & gas installations. They add local stiffness to the riser, flowline, cable or umbilical, limiting bending stresses and curvature to acceptable levels.
The world’s largest bend stiffener was designed for a 240mm/ 9.5 inches diameter umbilical and installed by Subsea7. It has an overall length of 11.3 meters/ 37 feet and a base diameter of 1,315 mm/ 4.3 feet. The weight in air of the component is 8,340 kilograms/ 18,386 pounds. It required a total PU volume of 5,360 liters/ 1,416 gallons.
John Shaw, Product Group Manager from Trelleborg Offshore noted, “Extensive testing was done prior to installation and in practice the stiffener has demonstrated excellent correlation between theoretical analysis and experimental data.”