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254 SMO Valves (UNS S31254)
254 SMO is a super austenitic stainless steel with 6% molybdenum, offering exceptional resistance to pitting and crevice corrosion in chloride environments. Ideal for seawater, desalination, and aggressive chemical applications.
Material Specifications
UNS: S31254 | EN: 1.4547
Castings: ASTM A351 CK3MCuN
Forgings: ASTM A182 F44
PREN: >40 (Pitting Resistance Equivalent)
Available Valve Types
Size: 1/2" to 48" | Pressure: Class 150-2500, PN10-PN420
Why Choose 254 SMO for Seawater & Chemical Service?
Superior Pitting Resistance
PREN >40 provides exceptional resistance to pitting and crevice corrosion in chloride environments where 316L fails.
Seawater Compatible
Proven performance in seawater cooling, desalination (RO, MSF, MED), and offshore applications worldwide.
Chemical Resistance
Excellent resistance to sulfuric acid, phosphoric acid, chlorides, and organic acids in chemical processing.
High Strength
Higher mechanical strength than standard austenitic grades allows for thinner wall sections and weight savings.
254 SMO Chemical Composition
Key Difference: 254 SMO has 6% Mo vs 2-3% in 316L, providing PREN >40 vs ~25 for 316L
254 SMO Valve Types & Specifications
Applications
Desalination Plants
RO, MSF, MED systems
Offshore Platforms
Seawater injection, cooling
Chemical Processing
Acids, chlorides, solvents
Power Plants
FGD, cooling water systems
Pulp & Paper
Bleaching, chlorine dioxide
Pharmaceutical
High purity, corrosive media
254 SMO vs Other Materials for Seawater
Frequently Asked Questions
What is 254 SMO?
254 SMO (UNS S31254) is a super austenitic stainless steel with 6% molybdenum content. It offers exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking in chloride environments. The PREN exceeds 40, making it ideal for seawater and aggressive chemical applications.
What is the difference between 254 SMO and 316L?
254 SMO contains 6% molybdenum vs 2-3% in 316L, giving it significantly higher pitting and crevice corrosion resistance. 254 SMO has a PREN >40 compared to ~25 for 316L. This makes 254 SMO suitable for seawater service where 316L would fail.
What are the ASTM standards for 254 SMO valves?
254 SMO valve castings are specified per ASTM A351 CK3MCuN. Forgings are per ASTM A182 F44. Bar stock is per ASTM A479 UNS S31254. The European designation is 1.4547.
Can 254 SMO be used for seawater service?
Yes, 254 SMO is one of the best materials for seawater service. Its high PREN (>40) provides excellent resistance to pitting and crevice corrosion in chloride-rich seawater. It is widely used in desalination plants, offshore platforms, and marine applications.
What valve types are available in 254 SMO?
We manufacture 254 SMO ball valves (floating and trunnion), gate valves, globe valves, check valves (swing, dual plate, piston), butterfly valves, plug valves, and needle valves. Sizes range from 1/2 inch to 48 inches in Class 150 to Class 2500.
Related Materials for Seawater Service
Need 254 SMO Valves for Your Project?
We supply 254 SMO valves to EPC contractors, offshore operators, and desalination plants worldwide. Contact us for technical support and competitive quotations.