The importance of the MGPS Marine Growth Prevention

The importance of the MGPS (Marine Growth Prevention System)

Marine Growth in Sea Water pipes & Sea Chests. . is a cause of serious operational problems (black outs / propulsion loss) due to blockage of sea water flow:

Marine Growth in Sea Water pipes & Sea Chests. . can cause accelerated corrosion of sea water cooling pipes: -crevice corrosion due to restricted flow of water -acidic corrosion due to the decaying of marine life inside the piping. Leading to increased piping renewals

Description of an anodic copper dosing MGPS The system is based on electrolysis of copper & alumimium anodes which are fed with an impressed electric current from a control panel Dual action system protecting seawater pipework against biofouling and corrosion COPPER ANODE ALUMINIUM ANODE produces ions which are carried by the flow of seawater into the pipework system preventing marine growth (barnacles and mussels will not settle or multiply) produces ions which spread throughout the system for applying an anti-corrosive layer on the internal surface of sea water cooling pipes Sea chest mounted anodes Anodic reaction: Al 3+ +3 e Anodic reaction: Cu 2+ +2 e Cathodic reaction: 3 H 20 + 3 e 3/2 H 2 + 3 OH- Cathodic reaction: 2 H 2 O + 2 e H 2 + 2 OH- Production of Aluminium Hydroxide: Al 3+ + 3 OH- AL(OH)3 Strainer mounted anodes

Operation & Maintenance of the MGPS • • • Copper & Aluminium anodes are usually renewed during drydockings and according to their design life (2. 5 -5 years). More frequent replacement may be required depending on the actual consumption of the anodes. Control panel readings of current are recorded in MGPS maker’s log sheet. Log sheet is forwarded once a month to MGPS maker for an appraisal of the system. Current to each anode should be increased if marine growth is detected in sea water pipes and associated coolers. The higher the current setting the shorter the anode life. Ensure that cables are connected correctly after anodes renewal. Take Megger readings between anode cables & hull after anodes renewal. Anodes should be always immersed in the water (daily air purging of strainers is required). Wasted anodes MGPS log sheet