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interfering with other systems, pipelines and components.

Getting constructability wrong can have dramatic consequences for sched-

EPIC ules, costs, quality of installations, the ability to remediate defects or construc- tion errors, safety and possibly cause the need to dismantle mechanically completed systems to allow completion, testing or repair of other systems.

For example, in some industry situ- ations, the fange sealing face of large components such as valves were dam- aged during installation due to poor access or inadequate lifting facilities.

As a consequence, the following helium leak test failed and the only solution was to rework the fange face by machining.

That meant that, in the restricted space, the installation of the milling machine necessitated a large section of the adjoin- ing piping and related instrumentation to be dismantled. The high-pressure

Designing for tight spaces ore and more offshore oil and gas solutions tend to be modeling capable of optimizing spaces

Designing a tightly packed,

M free-swinging foating units and preventing physical clashes, such as asset owners seek fexibility and solu- solutions might not take into account complex turret system is one tions to exploit remote and deepwater how easy and practical it is to build, thing. Designing so it can be offshore felds. install and test the turret. A good design,

These vessels must be moored so which will work well in service, could built and then maintained they can rotate around a turret system be slow, costly and diffcult to fabricate, without causing hiccups is into which all the risers and umbilicals install and test.

another. Carlo Pellegrino of connect. Italian classifcation society RINA is

Turret technology is well-understood advocating including “constructability”

Italy’s RINA Services explains. as a design criteria. Constructability is and operators have considerable in- leak test failure introduced an unwanted the ease and effciency of fabricating, service experience of them. However, as safety issue, delay to the schedule, and installing and testing the main process units operate in deeper waters, there is an overall lower quality outcome because piping lines, subject to the design and a greater requirement for larger numbers brand new items had to be repaired integrity requirements of the installation. of heavier risers and umbilicals to pass before startup.

through the turret — an already restricted The philosophy behind constructabil-

Striking a balance space. ity is to ensure that each system, pipeline and component can be installed and While space congestion can be There is a balance to be struck between tested in a scheduled sequence without resolved at a pure design level, with 3D simplicity of design, effciency of

August 2015 | OE oedigital.com 38 038_OE0815_EPIC1_rina.indd 38 7/21/15 7:37 PM