Corrosion is a natural process that can cause costly damage to your business or residence.
Cathodic protection is a simple method of protection that works by connecting the metal that we want to protect to a more easily corroded “sacrificial metal.” The active, sacrificial method acts as an anode and the protected metal becomes a cathode. This means that the sacrificial metal corrodes instead of the protected metal.
Learn more about cathodic protection below.
What Does Cathodic Protection Do?
Cathodic protection controls a metal surface’s corrosion and is typically used to protect storage tanks, pipelines, offshore structures, and ships from corrosion. In some cases, cathodic protection can be used to prevent cracking from stress corrosion.
If you have metallic gas piping or an underground propane tank, it is critical to understand cathodic protection and how it can protect your equipment.
There are two main types of cathodic protection:
Sacrificial Anode Cathodic Protection
In this method, a more reactive metal, often zinc or magnesium, is connected to the structure. This sacrificial anode corrodes instead of the protected metal, thereby preventing the corrosion of the structure.
Impressed Current Cathodic Protection
In this approach, an external source of direct current is used to counteract the corrosion process. This method is often used when the structure being protected is large or where the environment is too aggressive for sacrificial anodes to be effective.
Cathodic protection is a crucial technique for extending the lifespan of metallic structures and ensuring their safety and integrity, especially in environments where corrosion is a significant concern.
Where Can Cathodic Protection Be Used?
Cathodic protection is used all over the world to protect a wide range of metallic structures across a variety of industries in a wide range of environments, including residential and commercial settings.
Some common applications of cathodic protection include:
- Storage tanks, natural gas pipelines, and home water heaters
- Metal reinforcement bars in concrete buildings and structures.
- Steel, water, or fuel pipelines
- Hulls of boats and ships
- Steel pier piles
- Offshore oil platforms and onshore oil well casings
- Galvanized steel
Protecting your propane tank from metal corrosion and rust
There are several ways to protect your propane tank from metal corrosion and rust:
- Paint the tank with an approved rust inhibitor paint.
- Connect protected metal to a more easily corroded “sacrificial metal” to act as the anode. The sacrificial metal then corrodes instead of the protected metal.
- Apply a current using an external DC electrical power source with Impressed Current Anodes, which is used to provide sufficient current to prevent corrosion of the metal.
**With all the above protection measures, a cathodic protection test must be conducted by a professional with a reading of at least -0.85 volts**
Galvanization is also used for corrosion prevention of steel tanks. Cathodic protection is obtained by applying a layer of metallic zinc, by either hot-dip galvanizing or electroplating, to the protected object. Zinc is traditionally used because it is less expensive, it adheres well to steel, and it provides Cathodic protection to the steel surface in case of damage to the zinc layer.
Contact RP Gas Piping For More information on Cathodic Protection
Cathodic protection is a critical part of an underground gas piping system. It can protect your system and save you from costly damages. Our professionals help clients all around Arizona by testing their propane tanks for corrosion and rust. After testing we can recommend the best form of protection for your equipment. We can also help with any other propane tank or gas line piping needs. Learn more by contacting us today, or call (602) 759.8340.
SAFETY FIRST! An annual CP test is recommended in Phoenix, Arizona for all metal fuel systems below grade.
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