Super Duplex Stainless Steels (SDSS) are finding increasing use in high pressure feed pipework systems on SWRO plants and in other desalting applications using membrane technology. This paper details the corrosion resistance of ZERON 100 SDSS in seawater service, comparing and contrasting this with other grades of steel commonly used in SWRO applications. Key aspects of product design that allow for the construction of lower cost, more mechanically efficient pipework systems and vessels are detailed. Again these are compared and contrasted with other steels used in SWRO plants. Fabrication practices and procedures are discussed and welding, forming, machining and galvanic compatibility with other steels are considered. Specific case studies are presented where ZERON 100 SDSS has been successfully used in small scale and large scale new build SWRO applications. Also presented are cases where the alloy has been successfully used to replace SWRO pipework constructed in other grades of stainless steel that have suffered corrosion failure in service. Finally the successful use of the steel in novel membrane systems on offshore platforms is also presented.