Cathodic Protection Systems

Corrosion can destroy the integrity of your infrastructure.  Patching the damaged area may seem the simplest and least expensive process of repair, but it may also be the least effective.  Eventually, repairs may be required on a cyclical basis—each time growing more expensive.  These repairs weaken the structure and may lead to the need for total replacement.  We can provide you with a cost-effective corrosion control system designed to protect your infrastructure, prevent corrosion in new structures, and mitigate corrosion in existing structures -- saving you money.

How does cathodic protection stop corrosion?

Cathodic protection prevents corrosion by converting all of the anodic (active) sites on the metal surface to cathodic (passive) sites by supplying electrical current (or free electrons) from an alternate source.
 
Usually this takes the form of galvanic anodes, which are more active than steel. This practice is also referred to as a sacrificial system, since the galvanic anodes sacrifice themselves to protect the structural steel or pipeline from corrosion.

How do we know when we have enough cathodic protection?

We can verify that there's enough current by measuring the potential of the steel against a standard reference electrode, usually silver silver/chloride (Ag/AgCl sw.), but sometimes zinc (sw.).
 
Current flow onto any metal will shift its normal potential in the negative direction. History has shown that if steel receives enough current to shift the potential to (-) 0.800 V vs. silver / silver chloride (Ag / AgCl), the corrosion is essentially stopped.
 

For more information: CathodicProtection101.com