GUIDANCE FOR INSPECTION OF ATMOSPHERIC, REFRIGERATED AMMONIA STORAGE TANKS
1. SCOPE 4 2. INTRODUCTION 4 3. DESCRIPTION OF SPECIFIC AREAS OF CONCERN 7 3.1 Ammonia Storage Facilities 7 3.2 Types of Ammonia Storage Tanks 7 3.3 Ancillary Equipment 12 3.4 Design and Materials of Construction 12 3.4.1 Materials of construction 12 3.4.2 Pressure relief devices 13 3.5 Factors affecting the Integrity of Ammonia Storage Tanks 13 3.5.1 Original weld defects 13 3.5.2 Corrosion 13 3.5.3 Stress corrosion cracking 14 3.5.4 Low cycle fatigue 18 3.6 Indications from Accidents 18 4. INSPECTION STRATEGY 21 5. INSPECTION 24 5.1 Competence and Independence 24 5.2 Assessment for Inspection Frequency 24 5.3 Structural Integrity Calculations 26 5.4 Integrity Inspection from Inside 27 5.5 Non-Intrusive Integrity Inspection (from outside) 29 5.6 Other Inspection Issues 36 5.7 Leakage Monitoring System 37 5.8 Reporting 37 6. EVALUATION, REPAIRS AND CORRECTIVE ACTIONS 38 6.1 Evaluation 38 6.2 Repairs 38 6.3 Corrective Actions 39 7. COMMISSIONING, DECOMMISSIONING AND RE-COMMISSIONING 3
