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In-Service AST Inspection Report <br /> Formal External Inspection of 10,000-Gallon Tank(AST-1) <br /> Valley Pacific Petroleum Services,Inc.-Stockton Facility <br /> Page 4 <br /> emergency relief venting installed as required by the National Fire Protection <br /> Association (NFPA) uniform fire codes and NFPA 30 flammable and <br /> combustible liquid codes. <br /> 1.9.3. Tank liquid level gauges for both compartments were installed and visible along <br /> the northwestern containment wall. Condor inspectors used a graduated stick <br /> gauge to compare with installed tank level gauges. The northern compartment <br /> inspector measurement was 24 inches; 2 inches lower than the gauge reading of <br /> 26 inches. The product level in the southern compartment measured 31-inches <br /> and matched the gauge reading. Overfill alarms or vent whistles were not <br /> installed. <br /> 1.10. Grounding equipment was not installed on AST-1. <br /> 1.11. The tank was not equipped with stairways,handrails, or platforms. <br /> 1.12. Surface coatings observed on all surfaces of the tank shell, heads, and supports appeared <br /> to be in good condition. Maintenance of the tank's protective coating is strongly <br /> recommended to prevent external corrosion of the tank shell,pipe-fittings, and piping. <br /> 2. Original Shell Thickness of the AST <br /> 2.1. Original tank documentation was not provided for review. <br /> 2.2. The tank manufacturer was determined by examining the nameplate installed on the tank. <br /> 2.3. The tank's nameplate identifies it with an Underwriters' Laboratories (UL) designation. <br /> This indicates the tank is manufactured to the UL 142 specification for aboveground <br /> storage of flammable liquids. <br /> 2.4. According to several ultrasonic thickness(UT)measurements,the original shell thickness <br /> is presumed to be approximately 0.250 inches or 1/4-inch rolled steel with an average <br /> thickness of 0.256 inches of remaining steel. The original thickness of the tank's heads is <br /> presumed to be approximately 0.250 inches or 1/4-inch rolled steel with an average of <br /> 0.260 inches of remaining steel. <br /> 3. Horizontal ASTs <br /> 3.1. Shell plates, welds and ancillary equipment were inspected for indications of exterior <br /> corrosion, buckling, distortion due to stress, cracking, pinholes and mechanical damage. <br /> There were no signs of corrosion or damage on the exterior tank surface. Minor leakage <br /> from ancillary piping at both pumps mounted on the tanks topside. <br /> 3.1.1. UT measurements and visual inspection of the tank shell revealed no significant <br /> internal or exterior corrosion. Refer to the thickness measurements and <br /> photographs attached to this report. <br /> 3.2. The tank shell was inspected for indications of modifications that may have been made in <br /> the past. Brackets and platforms for ancillary tank equipment and piping appear <br /> consistent with the original design. No evidence of modification to the original tank was <br /> identified. <br /> 3.3 INSPECTION SUMMARY <br /> The following sections provide a summary of the inspection completed for the tank. <br /> UT Measurements Summary <br /> To obtain the residual metal thickness readings, a NDT Systems TG 110—DL ultrasonic digital thickness <br /> meter equipped with a TG-560P transducer was used. The meter has a resolution of±0.001 in (±0.025 <br /> mm) intended for use on steel plate and piping materials used in storage tank applications. The meter is <br /> capable of collecting readings using a scan mode or single point mode. The meter is factory calibrated <br /> (November 23, 2016) and proper operation confirmed prior to and during testing using a steel calibration <br /> �� CONDOR <br />