EVALUATION OF EFFECT OF INSULATION MATERIALS TO CORROSION RATE FOR CORROSION UNDER INSULATION (CUI)

Corrosion under insulation (CUI) is external corrosion due to the collection of water in annulus space between the insulation and the metal surface. CUI cannot be eliminated, but it can be managed. A suitable insulation material is required in order to control the CUI. In this project, a study of the impact of insulation material to corrosion rates will be performed. The test will be conduct by using several types of material for the insulation to analyze the corrosion rates. The Objective of this project is to analyze the result and establish the relationship between insulation material and the corrosion rate base on the data obtained following the guideline in API 581. The test is based on recently published ASTM G189-07 Standard Guide for Laboratory Simulation of Corrosion under insulation. The CUI cell consisted of six carbon steel ring specimens separated by insulated spacers and held together by blind flanged pipe sections on both ends. Thermal insulation which was placed around the testing section provided the annular space to retain the solution which represents the test environment. The ring specimens were used to test electrodes in two separate electrochemical cells. Corrosion measurements were made using mass loss data under isothermal test conditions. Several experiments been done to measure the corrosion rate at different material insulation which is Rockwool, Perlite, and Calcium Silicate. By using Rockwool insulation material, has the lowest corrosion rate compared with Perlite and Calcium Silicate insulation material