Check Valves for Offshore & Subsea Applications
NORSOK M-630, API 17D, and DNV-certified Duplex/Super Duplex and Inconel valves for topside process, subsea wellhead, FPSO, and offshore platform applications.
Which check valves are used for offshore & subsea applications?
Offshore and subsea valve applications represent the harshest operating environment in the industry - continuous seawater splash zone exposure, high-pressure/high-temperature (HP/HT) reservoir fluids, sour (H₂S-containing) gas, and the need for ESD (Emergency Shutdown) response times measured in seconds. Vajra Industrial Solutions supplies NORSOK M-630-certified Duplex 2205 and Super Duplex 2507 ball, gate, and butterfly valves for topside topsides; Inconel 625-clad valves for subsea trees; and SIL 2-rated actuated packages for ESD service on FPSOs, jackups, and fixed platforms.
Check Valve (Duplex)
Production header, gas lift, and chemical injection back-flow prevention
Critical Requirements
- NACE MR0175 / ISO 15156 compliance for all sour service valves - H₂S partial pressure thresholds define material selection
- NORSOK M-630 material qualification - specific hardness limits and chemical composition requirements beyond NACE
- Fire-safe design per ISO 10497 for all production valves - metal-to-metal seat backup required in tropical and North Sea environments
- SIL 2 or SIL 3 certification for ESD valves - IEC 61508/61511 failure mode and diagnostics documentation required
- Cathodic protection compatibility - valves in splash zone or submerged must be compatible with CP system (sacrificial anodes/ICCP)
- DNV or Lloyd's Register third-party type approval for safety-critical offshore valves
Service Challenges
- Sour crude (H₂S > 0.0003 MPa partial pressure) - sulfide stress cracking (SSC) and hydrogen-induced cracking (HIC) risk; NACE MR0175 mandatory
- Seawater (Cl⁻ > 19,000 ppm) - crevice corrosion and pitting; Super Duplex 2507 (PREN ≥ 40) minimum for submerged service
- High-pressure gas (>300 bar HP/HT wells) - gas permeation through elastomers; metal-to-metal seat or HNBR seats only
- Produced water with sand - erosive flow; hardened Stellite 6 trim or ceramic-coated trim
- Methanol, corrosion inhibitor, and scale inhibitor chemical injection - SS316L minimum for small-bore injection valves
Vajra Check Valves
Non-return valves to prevent backflow and protect equipment in piping systems.
See the full Check Valves rangeOther valves for offshore & subsea applications
Check Valves for other applications
Connected Engineering
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