Seawater Pump Corrosion Protection

Abstract

Assembly for the cathodic protection of a from galvanic corrosion suffering active component, which transports corroding medium, within a steel tube or casing containing a corroding medium. A plurality of anodes is equally distributed across the annular gap, while avoiding that these anodes are galvanically contacting the active component, e.g. pump, and one or more of the casing and tube or other component within the casing, other then through the corroding seawater, and a switching galvanic circuit. These anodes are suspended from a riser contained within the casing and providing the extension of the active component.

1 - 5 . (canceled) 
     
     
         6 . Assembly for the cathodic protection of a from galvanic corrosion suffering active component, which transports corroding medium, within a steel casing containing a corroding medium, wherein anodes of substantially equal length are suspended from only a single longitudinal end and are circumferentially distributed around the active component while co-extending next to each other and being spaced from both the casing and active component. 
     
     
         7 . Assembly according to  claim 6 , wherein remote from their suspended end the anodes are interconnected by a circumferentially extending spacing bracelet, providing a closed loop around and spaced from both the casing and active component and galvanic isolated spacers are active between the assembly of anodes, on the one hand, and the casing and active component, on the other hand, to keep the spacing bracelet, and thus the associated anodes, in a predetermined, centred position relative to the casing and active component. 
     
     
         8 . Assembly according to  claim 7 , wherein the active component is a water pump which is concentrically mounted within a circumferentially spaced carbon steel protective tube like casing located in a body of seawater, the annular gap between active component and casing is flooded with said seawater, which gap has a width at least 10 centimetre and not more then 50 centimetre and the diameter of the casing is at least 1 metre and not more then 2 metre, while the active component is galvanically more noble relative to the casing, since the active component is made from bronze or stainless steel, substantially for its complete length and the casing is substantially continuous along its complete length and the active component is an extension of another component wherein said two components are galvanically mutually connected, while the anodes are suspended from their top end and are with their top end fixed above the active component while their bottom end is at the level of the active component or its drive and the back of the anodes face the casing, which back of each anode is completely covered by a galvanically isolating coating, and each anode covers an axial length of at least 1 metre and the anodes and the component(s) they protect are mounted such that they exclusively make galvanic contact with each other through the corroding seawater and a switching galvanic circuit. 
     
     
         9 . Assembly according to  claim 8 , wherein a plurality of anodes is equally distributed across the annular gap, circumferentially and axially, while avoiding that these anodes are galvanically contacting the active component, the casing and any other component within the casing, other then through the corroding seawater, and the switching galvanic circuit and these anodes are suspended from a riser concentrically contained within the casing and providing the extension of the active component and the annular gap.