Zinc anodes have been used since the 19th century to protect steel structures from corrosion. Today, these anodes are still widely utilized and have proven to be an effective choice for preventing corrosion in select soils and brackish waters. Using zinc for cathodic protection enables the protection of SP pumps against corrosion caused by chloride-containing liquids, such as brackish water and seawater. Chloride-containing liquids are very aggressive to stainless steel. Especially in still liquids stainless steel will be exposed to corrosive attack in the form of localized corrosion, such as pitting and crevice corrosion. By fixing sacrificial anodes on the outside of the pump, the pump is protected against corrosive attack. The size of the zinc anodes is reduced over time and therefore, the anodes require replacing at regular intervals. Due to space, it is not possible to fix zinc to the inside of the pump and therefore, the pump is not protected on the inside. To avoid corrosive attack here, the pump must run almost continuously meaning that the pump must not be stopped for more than 6

8 hours at a time.

The anode string is fitted to the outside of the pump/ motor as shown in the I&O Instructions. The anode strings are to be fitted according to the I&O Instructions. The diameter of pump/motor is increased by min. 40 mm when the anode string is fitted.