Why Super Duplex Trunnion Ball Valve for Seawater Desalination

Mar 28,2026

Author: Site Editor

When it comes to seawater desalination projects, frankly speaking, TSV Super Duplex Stainless Steel Ball Valves are the absolute best choice. Why? Because they utilize super duplex stainless steel, offering advantages that other valves simply cannot match: top-tier resistance to chloride corrosion, rock-solid mechanical strength, and an exceptionally long service life that far exceeds that of most other valves. In short, they solve the two major challenges inherent in seawater desalination: the corrosive nature of seawater itself and the rapid wear and tear on valves caused by high-pressure operation.

Unrivaled Corrosion Resistance in High-Chloride Seawater

The high chloride content in seawater is a factor that cannot be underestimated; it leads to severe pitting corrosion, crevice corrosion, and stress corrosion cracking—precisely the primary causes of valve failure in desalination applications. TSV’s super duplex stainless steel trunnion-mounted ball valves are manufactured using 2507 super duplex stainless steel, boasting a PREN (Pitting Resistance Equivalent Number) value exceeding 40. In comparison, the PREN value of 316L stainless steel is merely around 18; consequently, the performance of TSV valves far surpasses that of the latter. Tests conducted by the British Stainless Steel Association have confirmed that their resistance to chloride-induced stress corrosion cracking is significantly higher than that of standard austenitic stainless steels.

Here is another interesting fact: during a test conducted in simulated high-temperature seawater conditions, the corrosion rate of TSV valves was a mere 0.0018 millimeters per year. And what about 316L valves? They failed after just eight months. This level of reliability means no unplanned downtime and no need for costly replacements—just smooth, continuous operation.

Exceptional Mechanical Strength Required for High-Pressure Desalination

Seawater desalination relies heavily on reverse osmosis and high-pressure pumping, which means valves must be robust, durable, and exceptionally stable. TSV’s super duplex stainless steel trunnion ball valves feature a minimum yield strength of 550 MPa—nearly double that of 316L stainless steel. What does this mean for you? It allows for thinner wall designs without compromising performance, thereby reducing overall weight and lowering installation costs. Its fixed trunnion structure securely anchors the ball, ensuring it remains free of deformation even under pressures ranging from 600 to 2500 lbs. This guarantees zero leakage, even during cyclic high-pressure operations. After a desalination plant in the Middle East switched to TSV valves, high-pressure pipeline vibration was reduced by 40%. Furthermore, maintenance intervals were extended from every six months to once every three years—a change that undoubtedly resulted in significant time and cost savings.

TSV Desalination Project Customization and Services

TSV does not offer one-size-fits-all solutions; instead, we provide solutions meticulously tailored to the specific needs of desalination projects. Our valves are available in sizes of 2 inches and larger, with pressure ratings reaching Class 2500 and beyond, making them perfectly suited for reverse osmosis systems, as well as pre-treatment and post-treatment units. Each valve complies with API 607/ISO 10497 standards, embodying exceptional quality and reliability.

Our engineering team does more than just sell valves; we collaborate closely with you on material selection, structural optimization, and even anti-corrosion coatings—measures that can extend a valve's service life by up to 30%. For instance, a desalination project in Spain utilized our custom-engineered trunnion ball valves; their full-bore, low-flow-resistance design significantly reduced system energy consumption by 8%, earning high praise from the client.

Conclusion:

In the field of desalination, Super Duplex stainless steel trunnion ball valves represent the optimal choice. They offer unparalleled corrosion resistance, high structural strength, and an exceptionally long service life—qualities unmatched by other valve types. TSV stands out from the competition thanks to our deep expertise in materials science, our proficiency in custom engineering, and our unwavering commitment to rigorous quality control. Consequently, our valves have become the preferred choice for desalination projects worldwide.