Cathodic Protection Design for FPSO’s

Description

What this Excel Sheet does
This excel sheet helps the user estimate the number of anodes required for corrosion protection of an FPSO or other floating production installation (FPI), depending on the properties of the anode supplied and the surface area needed to be protected
Calculates the Initial, Mean and Final currents required for cathodic protection
Treats Hull and Tanks separately for calculation as per DNV-RP-B101. High Corrosion areas in tanks are also taken into account
Calculates the current output of the anode based on properties supplied by the user
Calculates the total number of anodes required based on Anode Weight/Current required
Very useful in determining the number of anodes needed for Cathodic Protection of the FPI, and also in selecting the right anode type for the ship
Based on DNV-RP-B-101 RECOMMENDED PRACTICE Corrosion protection of floating production and storage units

Directions for Use
1. All the cells which require input are in the Worksheet ‘Inputs’ and have a blue background. Please fill only input cells, i.e., ones with a blue background. Leave the other cells untouched, as they are output cells
2. Fill in the inputs in the Worksheet ‘Inputs’. Please don’t fill anything in the worksheets named ‘Outputs – ”
3. Once the ‘Inputs’ sheet is completed, the calculations will be carried out to provide the number of anodes required to protect the desired area

Assumptions and Limitations
1. Resistivity for Temp < 5 degrees is the same as that for 5 degrees,
2. Resistivity for Temp > 25 degrees is the same as that for 25 degrees
“3. It is assumed that surface preparation has included blast cleaning
to a minimum SA 2.5 in accordance with ISO 8501”

References
“1. DNV Recommended Practice DNV-RP-B101 Corrosion protection of floating production
and storage units, Jul 2015”
2. DNV Recommended Practice DNV-RP-B401 CATHODIC PROTECTION DESIGN, October 2011