Stainless Steel Bolted Tanks Used in Sea Water Treatment Project in Saudi Arabia
Chinese Company Constructs Landmark Rabigh 4 Seawater Desalination Project in Saudi Arabia (2025-03-11)
A Chinese enterprise is building the landmark Rabigh Phase 4 Independent Water Project (IWP) in Saudi Arabia, a flagship project in China-Saudi water sector cooperation. The project features a highly modular design, which includes the construction of eight massive stainless steel water storage tanks. Each tank has a diameter of 100 meters and stands 19 meters high. Upon completion, the plant will have a daily production capacity of 600,000 tons of potable water, significantly boosting the region's water security and sustainability.
Modular assembly technology for ultra-large stainless steel storage tanks
Constructing an ultra-large stainless steel water storage tank with a diameter of 100 meters and a height of 19 meters would present challenges if traditional on-site welding were used, including long construction periods, difficulty in controlling welding quality, high on-site operational risks, and heavy reliance on local labor skills.
Modular assembly refers to the process of prefabricating tanks into standard modules such as wall panels and roof panels in a factory, which are then transported to the site for rapid mechanized assembly and connection.
About the material: Why choose stainless steel ?
In the field of seawater desalination, the choice of storage tank material directly affects lifespan, cost, and safety. The selection of “stainless steel” was a key decision for this project, underpinned by profound considerations:
1. Superior Corrosion Resistance (Core Advantage)
Media: Stored is treated desalinated water (pure water). While pure water poses no risk of chloride ion corrosion, it still exhibits slight corrosiveness and is sensitive to leaching from the material.
Advantages of Stainless Steel: Especially with the selection of austenitic stainless steel (such as 304, 316L), it possesses excellent corrosion resistance to pure water, ensuring water purity and freedom from rust contamination over a decades-long service life.
2. High Strength and Lightweight
Compared to traditional carbon steel with anti-corrosion coating, stainless steel offers a higher strength-to-weight ratio. While meeting the same design pressure, thinner plates can be used, reducing the tank's weight and facilitating “lower foundation costs” and modular installation.
3. Maintenance-Free and Long Lifespan Cost-Effectiveness
Maintenance-Free: The stainless steel surface forms a dense passivation film, eliminating the need for regular inspections and recoating of the anti-corrosion layer like carbon steel tanks, significantly reducing maintenance costs and downtime risks during operation.
Long Lifespan: Designed for a lifespan of over 40 years, with 100% recyclable materials at the end of its lifespan, offering outstanding economic and environmental benefits throughout its entire life cycle.
4. Hygiene and Environmental Protection
The smooth surface of stainless steel is resistant to bacterial growth and impurities, meeting the highest standards of drinking water hygiene.
The material itself is environmentally friendly and harmless, eliminating the risk of chemical leaching from coatings.
5. Considerations Compared to Other Materials
vs. Carbon Steel + Lining: Avoids the risk of lining aging and damage, resulting in higher reliability.
vs. Concrete: Faster construction, lighter weight, better sealing, and more suitable for modular construction.
vs. Fiberglass Reinforced Plastic (FRP): Under such large diameter and pressure requirements, stainless steel has a greater advantage in structural reliability and long-term performance stability.