Butterfly Valves for Seawater Service
Which butterfly valves configuration suits Seawater, in which material, to which standard — from real service data, with the pitfalls flagged.
Which butterfly valves for Seawater?
Super-duplex butterfly valve - PREN >40, handles high chloride seawater - offshore standard Rubber-seated butterfly valve (EPDM) - Cost-effective for large diameter, low-pressure seawater service Typical service window: 0.5–25 bar - seawater lift to process system, 0–40°C (ambient seawater); up to 120°C in desalination brine.
Recommended Configurations
Super-duplex butterfly valve
PREN >40, handles high chloride seawater - offshore standard
Rubber-seated butterfly valve (EPDM)
Cost-effective for large diameter, low-pressure seawater service
Body Material for Seawater
Rated from real compatibility data - click any material for the full decision page.
Governing Standards for Seawater Service
What to Avoid in Seawater Service
- Carbon steel without cathodic protection and coating
- Standard 304 or 316 stainless steel valves
- Valves with aluminium bronze trim in high-velocity seawater
Service Considerations
- PREN (Pitting Resistance Equivalent Number) ≥ 40 required for offshore seawater
- Anti-fouling coatings or PTFE lining to prevent biofouling
- Cathodic protection (zinc anodes) for submerged valves
- All crevices must be minimised - NORSOK M-001 crevice-free design
- Full-bore valves preferred to minimise biofouling accumulation
Other valve types for Seawater
Butterfly Valves for other services
Connected Engineering
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