Industry Solutions

Offshore & Marine Pipes

Super duplex, copper nickel, and nickel alloy pipe solutions for FPSOs, offshore platforms, shipbuilding, and desalination plants — class-approved, seawater-rated, and fully traceable.

ABS / LR / DNV / BV Approved PREN ≥43 Super Duplex Seamless & Welded Offshore Packing Available

Super Duplex & Copper Nickel Pipes for Marine & Offshore

Very few environments are as grueling for a pipe than the ocean. Saline water, continuous exposure to chlorides at variable temperatures, and the pressure of service place demands on the materials that hands down! Metinox Overseas has produced a complete line of pipe and tube products specifically for the offshore platform, subsea systems, and marine infrastructure coupling the durability of materials that can withstand extreme diversions. In addition, we source our materials directly from the manufacturer to ensure that every one of our materials will withstand the extreme offshore application. Tank materials made with Duplex and Super Duplex material give us the ability to create vessels that can withstand the pitting and cracking associated with the severe marine conditions in which they are used. Nickel alloys, specifically Inconel 625 and Incoloy 825, are used to withstand highly aggressive, sour-service applications.

To ensure efficient, cost-competitive solutions are available to support challenging projects, we partner with our customers including end-users; engineering companies; EPC contractors; and equipment producers. By matching the correct material selection to the application, platform piping, seawater system piping, riser piping; heat exchangers; structural piping, and so on, we work to provide the best possible reliability in some of the highest cost areas of failure.

Key Applications & Grade Rationale

Key Applications

  • Seawater cooling systems on FPSOs, semi-submersibles, and drillships
  • Seawater injection lines for reservoir pressure maintenance (HP/HT service)
  • Ballast water treatment system (BWTS) piping per IMO D-2 standard
  • Fire suppression and firewater mains on offshore platforms
  • Subsea manifolds, Christmas trees, and jumper piping
  • Desalination plant evaporator tubes and brine circuits
  • Ship hull and bilge piping, stern tube assemblies
  • Offshore platform process piping and utility distribution headers

Why These Grades?

Super Duplex S32750 / S32760 The preferred grade for seawater injection and firewater lines — PREN ≥43 ensures no crevice or pitting corrosion even in stagnant seawater.
Copper Nickel 90/10 (UNS C70600) Global standard for ship seawater cooling — biofouling resistance and proven 30+ year service life in marine heat exchangers.
Copper Nickel 70/30 (UNS C71500) Upgraded for higher seawater velocities (condenser inlet tubes) and elevated temperature applications.
Titanium Gr.2 Zero tolerance for marine corrosion; used in desalination evaporator tubes and offshore heat exchangers.
Duplex 2205 Cost-effective topside piping where S32750 PREN is over-specified.

Recommended Products & Grades

Product Recommended Grades Ideal Application
Super Duplex Pipes UNS S32750, UNS S32760 Seawater injection, firewater mains, subsea flowlines
Duplex Steel Pipes UNS S31803, UNS S32205 Topside utility, amine unit, produced water treatment
Copper Nickel Pipes 90/10 (C70600), 70/30 (C71500) Seawater cooling, condenser/HX tubes, ship piping
Inconel 625 Pipes Alloy 625, Alloy 825 Subsea wellheads, HPHT risers, clad pipe liners
Monel 400 Pipes Alloy 400 Seawater strainer housings, pump shafts, valve trim

Key Benefits

Class Society Approved Mills

ABS, LR, DNV, BV mill-endorsed MTCs — class-approved source documentation for every shipment.

Super Duplex Full Test Pack

Ferrite content, PREN verification, and Charpy impact test documentation supplied as standard.

CuNi Seawater Certified

Copper nickel pipes per ASTM B466 with seawater corrosion test certificates for marine service.

Offshore-Ready Packing

Wooden cradles, nitrogen purging, and end protectors for safe sea freight to any port worldwide.

Why Metinox Overseas — FAQs

Why Metinox Overseas?

  • Class society approved mill sources — ABS, LR, DNV, BV mill-endorsed MTCs
  • Super duplex pipes supplied with ferrite content, PREN, and impact test data
  • CuNi pipes per ASTM B466 with seawater corrosion test certificates
  • Established supply track record to Lamprell, L&T, SapuraKencana, NMDC
  • Offshore packing: wooden cradles, nitrogen purging, end protectors for sea freight
Why is super duplex preferred over 316L for seawater injection lines?
316L has a PREN of approximately 24, well below the ≥40 threshold required for immunity to pitting in seawater. In stagnant seawater, 316L suffers aggressive crevice corrosion within months. Super duplex S32750 with PREN ≥43 is immune to seawater crevice corrosion up to 30°C and pitting up to 50°C — providing 20+ year service life.
What is the velocity limit for copper-nickel 90/10 seawater piping?
CuNi 90/10 performs optimally at seawater velocities up to 3 m/s in straight pipe runs. Above this threshold, accelerated corrosion-erosion can occur at elbows and reducers. For higher-velocity systems (>3 m/s), CuNi 70/30 tolerates up to 4.5 m/s. Titanium has no practical velocity limitation.

Sourcing Pipes for an Offshore Project?

Class-approved, expedited supply with full traceability documentation for marine environments.