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API 653 In-Service Inspection Report for Pacific Ethanol HMT Inspection Tank No. T-6106 August 8,2013 Stockton, CA nage 5 of 46 2.0 SUMMARY AND REPAIR RECOMMENDATIONS The following is a summary of the significant findings of the inspection. FOUNDATION: The survey found the tank out of level by 2.75 inches. API 653 calculation for deflection of this tank is 2.16 inches. API 653 maximum deflection permitted for this tank is calculated at 0.71 inch. API 653 calculation for differential settlement does exceed the allowable (ref. API 653, Para. B.2.2). Normally, differential settlement is a good indicator of settlement related to foundation problems. In this instance, the tank rests on a raised concrete pad with no evidence of significant misalignment due to original construction. The survey was conducted counterclockwise from the reference shell Manway A located at Station 0.0 (Survey Point 1). The circumferential distance between the survey points is 20.4 feet The concrete pad has random hairline cracks present. These areas should be monitored for further degradation. If the cracking worsens, suitable repairs should be implemented. The moisture barrier has random areas of failed bond at the bottom edge projection, allowing water to enter under the tank bottom. A suitable moisture barrier should be installed around the entire tank bottom perimeter to minimize moisture from entering under the tank bottom which can lead to soil side corrosion. SHELL: Shell thickness calculations indicate the safe fill height of 40.0 feet can be utilized with product specific gravities up to 1.000. The hydrostatic test height can, therefore, utilize this maximum fill height(ref. API 653, Para. 4.3.3.2). These calculations do not take into account operational restrictions from such items as the high-level alarms or owner I operator-imposed safe fill restrictions. This tank is anchored against seismic and wind overturning loads with thirty-six (36) anchor bolts and chairs that are located every 55.5 inches (approximately) around the tank perimeter (centerline to centerline) and embedded into the concrete pad. These anchor bolts are each 1.375 inches diameter. Due to the number of anchor bolts presently installed, seismic and wind overturning anchorage is adequate as long as there is no corrosion metal loss to the bolts. There are no reinforcing plates present under the vertical ladder and automatic gauge supports. These details have been present for an extended period with no issues found and no corrective action is required at this time. These areas should be monitored in future for signs of accelerated corrosion due to possible increased stress concentrations. RECEIVED APIRPTNE.DOT REV 2 23262868/T-6106r(Rev 1) A i 15 3 1.5 A 'n 14 ENVIRONMENTAL HEALTH DEPARTMENT