Samenvatting

SBM Schiedam is active in the design, engineering and construction of Floating Production Storage and O oading (FPSO) ships. Currently SBM has a few projects for Petrobras. Purpose of an FPSO is to produce oil from a subsea oil eld. The FPSO production process is split over di erent modules which can be built simultaneously. A few of these modules are gas processing modules, where gas is treated and compressed. This compression process requires a centrifugal compressor which is connected to scrubbers and heat exchangers by piping. Because centrifugal compressors are sensitive rotating machines, they can take little nozzle loading. Industry supports this view and API subscribes a recommendation for allowable nozzle loads. These nozzle loads need to be adhered to as a minimum to guarantee proper functioning of equipment.

In order to stay below allowable nozzle loads. The piping system must be self supporting, that is to say it does not rest on the compressor system. This is just the start of a good design, in fact the compressor piping near the machine must be designed so that it is isolated from the e ects of the rest of the piping system. This forms the investigation of this report. To find the solution a basis of design is made, a design is proposed and this design is tested
by means of a finite element model.

The proposed solution is to design `isolation loops' around the compressor, which allow controlled thermal growth in the horizontal direction. The isolation loops are separate from the system by placing an axial stop in line with the xed point of the centrifugal compressor. Furthermore a spring hanger is tted for vertical support but allowing vertical growth. Isolation loops create an additional problem for some conditions to minimize this e ect a snubber
device is added to the loops.

The proposed solution works in theory and needs to be implemented in a working modeland if proven e ective, tried on a real module.