Cathodic protection in Plants

[vinod]

Sir,
We are providing cathodic protection system for plant equipments like UG piping, Tanks, etc. Can anybody explain why? How its works? Kindly give me some explanations
.

 

[ultramegabob]

a really simplified explination....

a really simplified explination....

you will be attaching a sacrificial anode to the metal that you are protecting (the cathode), it will be made of something like zinc that loses its electrons faster or easier than the steel or iron that it is protecting. the zinc will have to lose pretty much all of its electrons before the steel will start losing its electrons, which is what is happens during oxidization. Household water heaters use the same technology...

 

[LHarrington]

Good morning,
You are preventing galvanic corrosion. Most of the time when you combining two dissimilar materials together, such as aluminum and stainless steel the aluminum with deteriorate a rather fast rate. By adding a sacrificial anode to the components the anode will take the corrosion rather than the critical pieces. This is really popular in the boat motor world. In our case we have several Coolant transfer line with aluminum fitting and stainless steel lines on the inside of a larger braided hose. These anodes allowed us to extend the life of the coolant line and we were able to prevent using the floor and a spot store water and coolant.

LHarrington

 

[nakulak]

I have a book which does a rather good job explaining differrent types of corrosion, causes, contributing factors, and some methods of mitigation and abatement. Its called "the boatowners' guide to corrosion" by everett collier 2001 International Marine/McGraw Hill

 

[mdshunk]

They sell "anode bags" at the local HVAC supply house for use with buried propane tanks. Looks like a cloth sack with a piece of THHN coming out of it.

 

[mdshunk]

Picture of an anode bag:

 

[iwire]

Looks like a trench shoring violation to me. :wink:

 

[peter d]

They sell "anode bags" at the local HVAC supply house for use with buried propane tanks. Looks like a cloth sack with a piece of THHN coming out of it.

I always wondered what those were for. Now I know.

 

[niffur]

I always wondered what those were for. Now I know.

For extra credit, figure out for us why they are pouring liquid over the top of them.

 

[mdshunk]

For extra credit, figure out for us why they are pouring liquid over the top of them.

The anode bags were thirsty.

 

[vinod]

The anode bags were thirsty.

To be frank... i don't know why they puring water? kindly explain....

 

[mdshunk]

To be frank... i don't know why they puring water? kindly explain....

I don't know either. The anode bags do have absorbant material around them, so maybe they have to be wetted to be "activated"? I know those chamois cloths you dry your car off with don't absorb water worth a darned until you soak them with water and wring them out.

 

[nakulak]

In order for a galvanic cell to be created there must be 4 things present:
cathode (more nobler metal)
anode (less noble metal)
electrical connection between anode and cathode
an electrolyte (presumbably in solution)

this completes the cell. electrons transfer energy along the wire, while ions move through the solution in both directions.

I am guessing that they are saturating the ground in order to jump start the process of forming the electrolytic solution.

 

[kingpb]

Nakulak is correct; that instead of waiting for the bags to become saturated by ground moisture, they simply are getting them started.