Reducing seawater desalination costs with shut-off butterfly valves

Seawater desalination is a key technology employed to tackle the global lack of drinking water. In order to reduce its relatively high operating costs, operators and developers of systems and components are always seeking new cost-effective technologies. Desalination systems handle a very aggressive fluid, and the corrosion protection required for long-term and trouble-free operation is one of the cost drivers which make the process so expensive. Shut-off butterfly valves offer the possibility to save costs compared with other valve designs. On gate and globe valves, the entire flow path, or at least a large proportion of it, is wetted by the fluid handled. Therefore, these valves must be made from an expensive seawater-resistant material or at least provided with a plastic coating or an elastomer lining if this is possible from a manufacturing point of view.