| Cumberland Cathodic Protection Limited |
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The goal of Corrosion control is to eliminate the natural corrosion
process. A properly designed, equipped and installed cathodic
protection system is the only sure and safe way to protect immersed,
water-containing and buried metal structures from corrosion
process. A properly designed, equipped and installed cathodic
protection system is the only sure and safe way to protect immersed,
water-containing and buried metal structures from corrosion
Corrosion protection prevents corrosion by reversing the corrosion
process. By introducing positively charged anodes to the system
cathodic protection equalizes the electrical potential to all parts in the
structure. The flow of corrosive electrical currents is stopped and
corrosion is control.
Whereas paints and coating slow down corrosion attack by setting up
barriers, cathodic protection is positive and active: it suppresses attack
at the outset. Paints and coatings wear and deteriorate and are subject
to mechanical damage. Even a pin hole allows immediate onset of
corrosion at the surface of the metal; coating are undermined by the
products of corrosion and large areas are left completely open to
attack. Cathodic protection provides overall protection and is
independent of the conditions of the metal surface.
process. By introducing positively charged anodes to the system
cathodic protection equalizes the electrical potential to all parts in the
structure. The flow of corrosive electrical currents is stopped and
corrosion is control.
Whereas paints and coating slow down corrosion attack by setting up
barriers, cathodic protection is positive and active: it suppresses attack
at the outset. Paints and coatings wear and deteriorate and are subject
to mechanical damage. Even a pin hole allows immediate onset of
corrosion at the surface of the metal; coating are undermined by the
products of corrosion and large areas are left completely open to
attack. Cathodic protection provides overall protection and is
independent of the conditions of the metal surface.
| Direct current flow on a typical corroding structure |
C- Cathodic area
B – Current flows through the pipe steel from
cathodic area back to anodic area to complete the
circuit.
A – Anodic area: Where current leaves the steel to
enter the surrounding earth steel is being corroded.
D – Current flow through earth from anodic area to
cathodic area.
B – Current flows through the pipe steel from
cathodic area back to anodic area to complete the
circuit.
A – Anodic area: Where current leaves the steel to
enter the surrounding earth steel is being corroded.
D – Current flow through earth from anodic area to
cathodic area.
| Use of applied current to stop corrosion |
A - Originally anodic areas discharging current and
corroding
B- Dotted lines represent lines of current flow which
existed prior to applying protection and which have
been neutralized by the cathodic protection current
C- Protected structure
D- Current flowing from ground bed to surface to
protected structure
corroding
B- Dotted lines represent lines of current flow which
existed prior to applying protection and which have
been neutralized by the cathodic protection current
C- Protected structure
D- Current flowing from ground bed to surface to
protected structure
Cathodic protection is an Electro-chemical technique in which the
structure is protected against corrosion by applying an external
current in a direction opposite to that of the corrosion current.
The technique is used to protect existing as well as new structure.
structure is protected against corrosion by applying an external
current in a direction opposite to that of the corrosion current.
The technique is used to protect existing as well as new structure.
Cathodic protection current flows from the anode through the
electrolyte to the protected surface (cathode). The circuit is
completed by connection of the cathode to the power source. As the
current passes from the anode to the electrolyte the anode material
is slowly consumed. It flows then that corrosion is not eliminated by
the application of cathodic protection but is simply transferred from
the structure to the anode
electrolyte to the protected surface (cathode). The circuit is
completed by connection of the cathode to the power source. As the
current passes from the anode to the electrolyte the anode material
is slowly consumed. It flows then that corrosion is not eliminated by
the application of cathodic protection but is simply transferred from
the structure to the anode
