ToolFusion Chemical
ToolFusion Chemical
📋 Case Study

Nitric Acid Storage Tank MOC Failure Root Cause Analysis at Fertilizer Facility

Post-MOC leak occurred due to incompatible gasket material (EPDM vs. concentrated HNO₃)

🏗️ Project Overview

Upgraded secondary containment for 500,000-gallon nitric acid tank

🎯 Challenge

Post-MOC leak occurred due to incompatible gasket material (EPDM vs. concentrated HNO₃)

🔧 Design Approach

Bow-tie analysis identifying failure path; revision of MOC checklist to include chemical compatibility matrix and vendor data verification step

📐 Design Diagram

Nitric Acid Storage Tank MOC Failure RCABow-Tie AnalysisEPDM GasketCIR = 1.2 (Fail)MOC Checklist GapNo chem. comp. matrixViton® GasketCIR = 4.8 (Pass)Revised MOC+ Chem. Matrix+ Vendor Data CheckConcentrated HNO₃Storage TankGasket Array

AI-generated project design illustration

📐 Key Calculations

Compatibility Index Rating

CIR = Σ(material resistance scores)
Result: EPDM = 1.2 (Fail); Viton® = 4.8 (Pass)
Objective threshold for material approval

📊 Results

Zero repeat incidents in 36 months; MOC checklist adopted corporate-wide; integrated NACE MR0103 database into engineering workflow

💡 Lessons Learned

  • •MOC must verify *all* materials—not just primary vessel
  • •Vendor datasheets require independent lab validation for aggressive services

✅ Key Takeaways

  • 1MOC must verify *all* materials—not just primary vessel
  • 2Vendor datasheets require independent lab validation for aggressive services