Topside Module Fabrication

Modular construction moves work off the offshore critical path and into a controlled shop, where it is cheaper, safer and easier to inspect. The trade-off is that everything depends on the interfaces being right, because a module that does not fit is a very expensive object to correct at sea.

Meritus sources pre-assembled topside modules and process units from Chinese fabricators, with dimensional and weight control treated as a primary deliverable rather than a closing formality.

Capabilities

Process modules, PAUs and utility modules
Pipe rack and interconnecting modules
Integrated piping, E&I and HVAC pre-outfitting
Equipment support structures and skids
Dimensional control at defined hold points
Module weighing and CoG determination witnessed
Shop pressure and functional testing
Load-out and transport interface review

Scope we cover

Process modules and PAUs; utility and power generation modules; pipe rack and interconnecting modules; equipment support structures and skids; module steelwork with integrated piping, electrical, instrumentation and HVAC; access platforms, stairs and safety structures.

Dimensional and weight control

We require dimensional control surveys at defined hold points, not just at completion, so deviations are caught while they are still cheap to fix. Module weighing and centre-of-gravity determination are witnessed and reconciled against the design basis, because lifting arrangements and vessel stability both depend on those numbers being real.

Pre-outfitting and testing

The value of a module is in how complete it arrives. We push pre-outfitting as far as the transport envelope allows — piping, cable trays, instrumentation, insulation — and witness pressure testing, continuity checks and functional testing in the shop. Every order runs through the same quality chain: shop pre-qualification, material traceability against mill certificates, in-process and final inspection, and a documentation pack released before shipment.

Failure modes we inspect for

Dimensional surveys taken only at completion, when a deviation is already built in. Tie-in points correct in position but rotated. Weighing carried out with scaffolding still attached. Pre-outfitted pipework pressure-tested before final supports were installed, so the test does not represent the shipped condition. And preservation that was adequate in the shop and inadequate for eight weeks at sea.

How an order runs

Enquiry and specification review; shop shortlisting against the actual scope rather than a general vendor list; quotation with the inspection plan priced in, not added later; kick-off with agreed hold and witness points; in-process inspection at those points; final inspection, document pack release and shipment; arrival support if anything is queried. For modules we fix the dimensional hold points at kick-off and treat the survey results as release conditions.

Standards and certifications referenced

AWS D1.1
ASME B31.3
ASME Section VIII
ISO 8501 / ISO 12944
IACS UR W-series
ISO 9001:2015

Frequently asked questions

What is a PAU?

A pre-assembled unit — a section of plant built and outfitted in the shop, then transported and lifted into place as one piece, so that welding, piping and cabling happen in controlled conditions rather than offshore.

How much pre-outfitting is practical?

As much as the transport envelope and lifting arrangement allow. Piping, cable trays, instrumentation and insulation are commonly included; the constraint is usually shipping dimensions and module weight, not fabrication capability.

How are module interfaces controlled?

By dimensional survey against the 3D model at defined stages, with specific attention to tie-in point position and orientation, plus review of the transport and lifting arrangement before release.

What testing happens before shipment?

Pressure testing of pre-outfitted pipework, electrical continuity checks, instrument loop checks where practical, and preservation verification.

Request a Quote

Contact Meritus Technology's ISO 9001:2015 certified procurement desk in Shanghai for topside module fabrication — supplier verification, QA/QC, and global shipping. Request a quote or contact us.