Due to their ability to resist corrosion, Speciality valves made of super duplex are often quite useful in various industrial processes including seawater systems and desalination plants. These corrosion-resistant valves are extremely functional in marine conditions such as sub-sea, offshore, and platform work. Also, these severe service valves are perfect in the chemical industry, especially when dealing with a variety of corrosive agents such as the following:
- chlorides used in flue-gas cleaning
- steam
- fatty acids
- concentrate brine
- sea water
- pulp water
- potable water
- pulp liquors at 220°F (104°C)
- sulfuric acid (35-40% @ 185°F (85°C), plus 5% organics)
- sulfuric acid (15-30% @ 140-160°F (60-71°C))
Super duplex, used in exotic Speciality alloy valves, is a common name for a wide range of materials. Made of a 50/50 mixed micro-structure of austenitic and ferrite, super duplex stainless steel is much stronger than austenitic and ferritic steel grades that have similar corrosion resistant properties. This increased strength is caused by the augmented chrome and nickel content in their composition. The super duplex stainless steel used in exotic Speciality alloy valves ranges in type and grade dependent on the method the raw material was developed and dependent on the international standards and norms used.