Esso Norge's Balder Field FPSO will feature a non-welded hydraulic piping system from GS Hydro's Norwegian subsidiary. The FPSO, built by FELS in Singapore, is designed with a centralised hydraulic power pack providing power through a carbon steel piping system to the cargo pumps, deck cranes, winches, ancillary pumps and the bow offloading system.
GS Hydro has been supplying the piping under a turnkey package that includes all pipes and flanges, supervision at the yard and provision of the GS containerised workshop for the duration of the installation. This workshop includes a saw, GS lathe and flaring machines.
The main 280 bar WP pressure lines comprise intrinsically clean, cold drawn carbon steel tubes (maximum diameter 150 by15mm). Tube ends are prepared on site, joints being made simply by sliding a backing flange over the tube and fitting the GS `retain ring' into the pre-machined groove.
Tube sizes of 50mm and 60mm are jointed with the GS 37deg flare system. Branch lines are installed using tees that fit between the main jointing flanges. The 50 bar low pressure return lines (maximum size 220 by 6mm) are jointed by the GS 90deg flaring system, in which the tube end is rolled out to a 90deg flare like a lap joint. Backing flanges are used to complete the pipe connection.
According to GS Hydro, this system has clear advantages over conventional welded systems. Pipe preparation time is fast, pipework remains intrinsically clean, and there is no need for pickling or X-rays. Installation costs are therefore substantially lower and flushing time is also reduced.
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