Redesain Pipe Support Location Jalur Outlet Gas 2nd Stage Gas Lift Suction Scrubber Menuju Suction 2nd Stage Gas Lift Compressor Akibat Clash

Abstract

This study presents the stress analysis and redesign of the 12”-PG-B1-2303 piping system
within the gas compressor module of the Forel FPSO Time Charter project. The modification was
necessary due to a clash identified during construction between the pipe support and two adjacent lines
connecting the outlet of the second gas lift scrubber (23 MBF-002) to the inlet of the second compressor
package (23 CAE-002). Limited H-beam locations and restrictions on direct deck installation required
repositioning of the support. The allowable pipe span was evaluated using the Kellog, Kannappan, and
Timoshenko methods, with the minimum allowable span of 14.779 m adopted as the design reference.
Static stress analysis, conducted in accordance with ASME B31.3, confirmed the structural integrity of
the system. The support was relocated 1.021 m along the X-axis, producing maximum stresses of 8670.2
psi (43.4% allowable) for sustained load, 9946.5 psi (37.4%) for occasional load, and 4565.5 psi
(15.2%) for thermal expansion. Nozzle load verification yielded forces of 1560 lb and 1755 lb, with
corresponding moments of 8343.8 lb-ft and 7859.9 lb-ft for the scrubber outlet and compressor suction,
respectively. Material Take-Off (MTO) estimation resulted in a cost of IDR 194,387,569. The findings
demonstrate that all stress and displacement values remained within allowable limits, validating the
reliability and compliance of the redesigned configuration under ASME B31.3.