Fuel Gas Supply System Fabrication

As shipowners convert to LNG and methanol dual-fuel propulsion, the fuel gas supply system becomes the piece of equipment that decides whether the vessel can actually run on gas. It is also the piece most tightly governed by class and the IGF Code.

Meritus sources FGSS packages and sub-assemblies from Chinese fabricators and OEM partners, matched to the engine you have actually specified — high-pressure for ME-GI, low-pressure for X-DF and dual-fuel four-strokes.

Capabilities

High- and low-pressure FGSS for ME-GI, X-DF and four-stroke dual-fuel
Gas valve units (GVU) and gas heaters
LNG fuel tanks and tank connection spaces
Bunkering stations and manifolds
Double-walled gas piping with leak detection
IGF Code compliance and class approval coordination
Shop functional testing before delivery
As-built documentation aligned to fabrication

Scope we cover

Fuel tanks and tank connection spaces; high- and low-pressure pump and vaporiser skids; gas valve units (GVU); gas heaters and pressure build-up units; bunkering stations and manifolds; nitrogen and inert gas support; double-walled gas piping with annular ventilation and leak detection; associated gas detection and safety shutdown.

IGF Code and class

IGF Code compliance is not a certificate you add at the end — it shapes the arrangement, the ventilation, the material selection and the hazardous-area classification. We work to the class rules that apply to your flag and yard, coordinate the approval-in-principle and detail drawing approval, and keep the as-built documentation aligned with what was actually fabricated.

Testing and handover

Gas trials are the expensive place to find a problem. We push testing upstream: shop functional testing of the GVU and pump skids, cryogenic seat-tightness on gas-service valves, and pressure and leak testing of double-walled sections before installation. 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

Fabrication built to the enquiry drawing rather than the class-approved drawing — the two diverge more often than owners expect, and the as-built pack then fails approval. Double-walled sections pressure-tested on the inner line only. Ventilation and gas-detection provisions installed to a generic arrangement rather than the approved hazardous-area classification. And GVU skids where a component substitution was made without a documented request.

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 FGSS we align the fabrication scope against the class-approved drawing set at kick-off, and hold shipment until the as-built pack matches it.

Standards and certifications referenced

IMO IGF Code
IMO IGC Code
ASME B31.3
IEC 60079 (hazardous areas)
ISO 9001:2015
Class rules: DNV, ABS, LR, BV, CCS

Frequently asked questions

What is a fuel gas supply system?

The FGSS conditions LNG or another gas fuel from the storage tank to the engine at the pressure, temperature and flow the engine requires — pumps, vaporisers, heaters, the gas valve unit and the associated double-walled piping and safety systems.

Does the FGSS differ between ME-GI and X-DF engines?

Substantially. ME-GI is a high-pressure system operating at around 300 bar; X-DF and most dual-fuel four-strokes are low-pressure at roughly 6–16 bar. The pumps, vaporisers and piping class are not interchangeable, so the engine must be fixed before the package is specified.

What does IGF Code compliance actually require?

It governs arrangement, ventilation, material selection, hazardous-area classification, gas detection and the extent of NDT on gas piping. It shapes the design from the start rather than being certified at the end.

Can Meritus coordinate class approval?

Yes — we coordinate approval-in-principle and detail drawing approval with the class society for your flag and yard, and keep the as-built documentation aligned with what was approved.

Request a Quote

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