What Is the Sacrificial Anode Cathodic Protection Calculator?
Sacrificial galvanic cathodic protection utilizes more electronegative metals (Al, Zn, Mg) to act as sacrificial anodes for steel.
The anode corrodes preferentially, supplying protective electrons to shift the steel potential into the cathodic immune region.
How Does the Sacrificial Anode Cathodic Protection Calculator Work?
The current demand equals surface area times design current density.
Multiplying by operational hours and dividing by practical alloy capacity (e.g. 2600 A·h/kg for Al-Zn-In) yields the net required alloy mass.
Sacrificial Anode Cathodic Protection Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
Standard DNV-RP-B401 sacrificial anode mass calculation based on alloy electrochemical capacity.
How to Use the Sacrificial Anode Cathodic Protection Calculator
- Input steel surface area, design current density, lifetime in years, and utilization factor.
- Review total anode mass in kg, current demand in Amps, and annual consumption rate.
Step-by-Step Example Calculation
Offshore Platform Jacket Leg Protection
Input Values:
Understanding Your Result
Sufficient anode mass guarantees continuous protective current through the end of the design life.
Factors That Affect the Result
- Water temperature, salinity, and biofouling alter protective current requirements.
- Coating breakdown factor dramatically impacts required bare-steel current demand over time.
When Should You Use This Calculator?
- Offshore jacket design, subsea pipeline CP sizing, ship hull zinc installations, and buried tank protection.
Assumptions & Limitations
- Based on mean maintenance current demand in accordance with DNV-RP-B401 methodology.
Frequently Asked Questions
Calculation Accuracy & Reference Note
Standard offshore engineering design equation matching NACE and DNV codes.