When an LNG plant built in 1999 by CB&I faced a client request to increase pipeline send-out rates by nearly 60%, the engineering team turned to modern hydraulic modelling to validate that the expansion could be done safely. The result: using Datacor’s Impulse surge analysis software, CB&I demonstrated that higher throughput was feasible without exceeding key design limits, including line pressure and equipment force specifications.
Project background
The original facility was designed to deliver 64 800 ft3/hr (≈1800 m3/hr). The new requirement was to ramp that up to 102 600 ft3/hr (≈ 2900 m3/hr). A major concern was the pipeline’s boil-off gas (BOG) condensers and whether rapid valve closures (within three seconds) could trigger pressure surges beyond safe thresholds.
Since CB&I had designed the facility from the start, they had access to piping isometrics and a 3D model of the plant – resources which proved invaluable during modelling. Denis Escobar, a process engineer at CB&I, led the evaluation using Impulse. He constructed two scenarios: Pre-Expansion at current flow; and Expansion, with nearly 60% greater flow and additional capacity.
Modelling approach
Pre-Expansion scenario: flow of ~64 800 ft3/hr, all send-out from Tank A via three in-tank pumps (each rated 24 200 ft3/hr, ~160 m head, ~76.5% efficiency).
Expansion scenario: flow ~102 600 ft3/hr; send-out now from both Tank A and Tank B, using six in-tank pumps of the same individual ratings.
Using Impulse’s 3D model and its Visual Reports module, CB&I could not only run the simulations, but also create visual layouts showing equipment locations and pipeline routing in context. This helped stakeholders grasp how pressures and forces would shift under the expanded operating conditions.
Key findings
Pressure levels under the higher flow remained below the facility’s design maximum of 15.5 barG (≈225 psig), even factoring in potential surge events due to quick valve closures.
Force and stress analyses – using output from Impulse plus a separate stress engineering review – confirmed that, while forces increase under the new scenarios, they still fall within allowable design limits.
The ability to build side-by-side ‘before’ and ‘after’ models was especially useful, since there was no existing benchmark for the higher flow rate from earlier operations.
Main takeways
CB&I gained confidence that the plant expansion could go ahead without major redesign or replacement of primary piping. The use of Impulse’s isometric and visual reporting tools made it easier to communicate findings to both internal teams and third-party stress analysts. As Escobar put it: “By using the isometric modelling views with the Reports tools and capabilities the software has, it helps in presenting the results in a well-summarised approach.”
For LNG operators considering capacity increases, this case illustrates the importance of modeling tools that offer both hydraulic fidelity and visual clarity. Being able to scenario-test changes, check for pressure safety, and assess force impacts without intrusive field work can save time, CAPEX, and risk.
Conclusion
CB&I’s use of advanced flow modelling through Datacor’s Impulse demonstrates that even substantial capacity gains – such as a 60% increase in send-out flow – can be managed within existing plant constraints, provided the right analytical tools are applied. For LNG industry stakeholders, the case reinforces that growing demand does not always require building new infrastructure; sometimes what is needed is better insight into what is already available.
For more information please click here.