One of the problems in the oil and gas industry is the corrosion of the external body of underground tanks, which causes a lot of damage to these industries annually. Tanks external body cathodic protection is used as a complementary coating method to prevent this type of corrosion. The type and thickness of coatings used in underground tanks is particularly important and determines the amount of cathodic protection required current.
The Tanks external bottom cathodic protection is accomplished in two ways: sacrificial anode and impressed current. In the sacrificial anode cathodic protection method, usually is used magnesium or zinc anodes with the backfill, depending on the electrical resistivity of the soil. The impressed current cathodic protection method is used cast iron (HSCI) or mixed metal oxide (MMO) anodes depending on the required current rate and design life. Particular attention should be paid to the type and amount of protection when buried tanks contain sour products, as over protection can aggravate other corrosion mechanisms.
Schematic of buried tanks cathodic protection by impressed current method using wire MMO anodes
Schematic of buried tanks cathodic protection by impressed current method using tubular MMO anodes
Borna Electronics Co. with over 30 years of experience in cathodic protection, declares its readiness to design, procurement, consultation and construction of cathodic protection systems for underground tanks and vessels and implement cathodic protection monitoring systems for them.