Best Practices When Using Specialty Materials for SWRO Feed and Brine Reject Lines

Understanding Material Selection for SWRO: The journey begins by understanding the pivotal role of specialty alloys in SWRO systems. Rolled Alloys, a global supplier, offers a range of state-of-the-art materials, including nickel alloys, stainless steels, titanium, and cobalt alloys. Their expertise lies in providing technical assistance, laboratory services, and innovative solutions for the industry. 

Corrosion Resistance in Stainless Steels: Dr. Byrne, an industry expert, outlines the correlation between compositions of stainless steels and their resistance to corrosion. Factors like Pitting Resistance Equivalent Number (PREN) play a crucial role in determining the seawater resistance of these alloys. 

Historical Evolution and Challenges: The historical journey reveals the trial-and-error phase in material selection, highlighting challenges faced by using lower-grade stainless steels like 316. Instances of pitting and crevice corrosion led to the realization that higher-grade materials, like 6% molybdenum alloys and super duplex stainless steels, were better suited for SWRO applications. 

Transition to Advanced Grades: The late ’90s witnessed a transition towards advanced alloys, particularly super duplex stainless steels, as the industry embraced RO technology for larger municipal SWRO projects. This transition marked a significant shift from earlier materials due to their cost-effectiveness and superior performance. 

Challenges and Solutions in Material Selection: While 6% molybdenum alloys and super duplex stainless steels performed well, they weren’t immune to corrosion. Challenges such as crevice corrosion at connections and pitting corrosion of welds necessitated stringent adherence to best practices in manufacturing, fabrication, and treatment processes to minimize risks effectively. 

Conclusion: Rolled Alloys stands as an industry leader, offering specialized expertise and a robust supply chain for SWRO projects. Their commitment to delivering quality materials and technical support underscores their position as a reliable partner in this niche market.