DONG Energy operates the Siri field in the North Sea. During the work with the flare, relief and blowdown report for the Siri platform, Ramboll detected that the lead pipe pressure drop was above 3% of the PSV set-point on the lead pipes in the 26C compressor train.
Preventing pressure relief valve chatter
In case of a relief through the PSVs, the high pressure drop would result in pressure relief valve chatter, and as a consequence, the valve might be damaged and the required relief might not be obtained. In addition, the capacity of the PSV would be reduced.
Engineering and procurement
Ramboll carried out the design basis for new pressure safety valves (PSVs), new rupture discs (PSEs), new pipe routing and new supports based on a 3D model. Furthermore, Ramboll assisted DONG with procurement and expediting of the project.
From certification to commissioning
A certification, fabrication and installation package was prepared for the replacement of the lead pipes, tail pipes, PSV’s and PSE’s in the 26C compressor train to decrease the pressure drop. As a consequence of these modifications some pipe supports were replaced, new instrument design for PSEs was carried out, setpoints in the compressor control panel were changed and deluge coverage was modified. Finally Ramboll prepared a mechanical completion and commissioning package.
Ramboll’s scope of work included:
- Offshore scanning of the compressor area
- 3D modelling and detailed design of piping and supports
- Process design and calculations
- Pipe stress reports
- Instrumentation design
- Update of fire water report
- Certification, fabrication and installation package
- Mechanical completion and commissioning