The Effectiveness of Na<sub>2</sub>CrO<sub>4</sub> to Inhibit Corrosion Rate of a A106 Grade Pipe in the Furnace Circulating Cooling Water with the Weight Loss Method on Pipe Lifetime Determining

Abstract

Pipes from industrial process flow diagrams have a predictable risk of failure or damage, so that periodic inspections are carried out. Corrosion that occurs in the pipe can cause a risk of leakage or blockage of the pipe flow which can be fatal to the fluid distribution process. This damage can be anticipated by inhibitors adding and predicting the corrosion rate. This research was conducted to determine the effective concentration of Na2CrO4 inhibitor to inhibit the corrosion rate and predict the lifetime of the furnace cooling water circulation pipe using the weight loss method. Na2CrO4 inhibitor is a type of anodic inhibitor that works by passively the anode by inhibiting corrosion on a whole metal surface. The study begins with the preparation stage, cutting the pipe into specimens of a certain size, smoothing the surface and weighing the initial weight. The testing phase was carried out by immersing the specimens at various times of 120 h, 240 h and 360 h with Na2CrO4 inhibitor variations concentration was 0%; 0,3%; 0,6%; and 0,9%. The corrosion rate was calculated by re-weighing the specimen after the immersion process. The results showed that the most effective inhibitor concentration was 0.6% with a corrosion rate of 0.3021 mmpy and the Remaining Service Lifetime (RSL) was 9.399 years.