Marine & Offshore Service
Application Specification

Butterfly Valves for Marine & Offshore Service

Trunnion ball valves, butterfly valves and gate valves in Super Duplex (F53) and Duplex (F51) for FPSO, offshore topsides, subsea wellheads, and marine seawater service.

Which butterfly valves are used for marine & offshore service?

Offshore oil and gas platforms, FPSOs, subsea wellheads, and marine vessels present the most aggressive corrosion environment in industry: high-chloride seawater, saline atmosphere, cyclic wave loading, and continuous hydrocarbon exposure. Valves in these applications demand Super Duplex (UNS S32750/F53) or Duplex (UNS S31803/F51) stainless steel, compliance with NORSOK M-710 qualification testing, DNV-OS-D101 marine system requirements, and full NACE MR0175 sour service documentation.

Butterfly Valve (Duplex / Super Duplex)

Seawater cooling and ballast system isolation on FPSOs and offshore platforms - wafer or double-flanged, high-chloride resistant

MaterialsDuplex UNS S31803 body, Super Duplex disc for seawater, EPDM or PTFE seat
Pressure ClassPN 10 / PN 16 / Class 150 / 300
StandardsAPI 609, EN 593, DNV-OS-D101

Critical Requirements

  • Super Duplex (UNS S32750/S32760) or Duplex (UNS S31803) for all seawater-wetted surfaces - PREN ≥40 for super duplex
  • NORSOK M-710 elastomer qualification testing for FPSO and North Sea applications
  • NACE MR0175 / ISO 15156 compliance for sour (H₂S-containing) produced fluids
  • DNV-OS-D101 or Lloyd's Register certification for marine system valves
  • API 607 fire-safe design for hydrocarbon-carrying valves on offshore topsides
  • Cathodic protection compatibility - valves on submerged structures require galvanic compatibility

Service Challenges

  • Seawater (high chloride, microbiologically influenced corrosion) - standard SS 316 is insufficient; duplex or super duplex required
  • Produced water (oil + water + H₂S + CO₂ + chlorides) - combined NACE and duplex material requirement
  • Sour crude with H₂S - sulphide stress cracking; hardness-controlled NACE materials mandatory
  • Seawater injection for EOR - high-pressure, high-chloride; super duplex and NORSOK qualification
  • Marine atmosphere (salt spray, humidity) - external coating system: zinc primer + epoxy + polyurethane topcoat (NORSOK M-501)

Vajra Butterfly Valves

Compact and efficient butterfly valves for large-scale flow control and isolation.

See the full Butterfly Valves range

Other valves for marine & offshore service

Butterfly Valves for other applications

Reviewed by Product Engineering, Vajra Industrial SolutionsDiscipline: Valve Product EngineeringLast reviewed: 20 June 2026

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