Desalination Plants and the Rise of Duplex Stainless Steel 2205 Pipes

Published on 28 September, 2025

As global water scarcity is becoming a worrisome issue, desalination as a term has emerged as the only critical solution to ensure a sustainable freshwater supply. Countries around the globe with limited natural water reserves and industries that are heavily using water resources are now investing heavily in desalination plants. These facilities not only convert seawater into potable water through reverse osmosis (RO) and multi-stage flash distillation (MSF) but also. However, it has its own share of challenges; it's nothing but a harsh environment created by seawater’s high chloride content, which accelerates corrosion in traditional piping systems. This is exactly where Duplex Stainless Steel 2205 pipes are becoming the material of choice. 

 

Why Advanced Alloys are Essential

 

Seawater is rich in chlorides, sulphates, and oxygen that degrade carbon steel and even austenitic stainless steels like 304L or 316L. Under high pressure and fluctuating temperature, piping can suffer pitting, stress corrosion cracking (SCC), and erosion. Failures not only demand expensive repairs but also risk halting the vital water supply.

 

Duplex Stainless Steel 2205 – The Preferred Material

 

Duplex Stainless Steel 2205 (UNS S32205/S31803) is a two-phase alloy with both austenite and ferrite. Its structure gives it remarkable mechanical strength and superior resistance compared to traditional grades.

 

Key benefits:

1. Strong defence against chloride-induced pitting and crevice corrosion.
2. Excellent resistance to SCC in salty environments.
3. Nearly double the strength of standard austenitic grades, allowing lighter, thinner pipes.
4. Good weldability and toughness are essential for plant fabrication.

 

Duplex Stainless Steel 2205: Applications and Impact

 

Duplex 2205 pipes are widely applied in RO feedwater lines, brine discharge, evaporators, manifolds, tanks, and heat exchangers. Although the upfront cost is higher than carbon steel, the life-cycle cost is lower, with fewer failures and reduced downtime.

 

As desalination capacity expands globally, Duplex Stainless Steel 2205 pipes are proving indispensable. Their durability, corrosion resistance, and efficiency ensure plants can reliably deliver potable water while supporting long-term sustainability.

At Online Fittings, we understand the growing demand for high-performance materials in critical industries like desalination. That’s why we offer a complete range of Duplex Stainless Steel 2205 pipes, tubes, and fittings designed to withstand the toughest environments. Whether it’s for RO feedwater systems, brine outlets, or large-scale heat exchangers, our products deliver reliability and long service life.