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1) Steel plates for storage tanks a. Use Q235-B/Q345R and should meet the requirements of the ordering technical conditions. Takeovers and accessories should have quality certificates. b. Welding rods used for tank welding should comply with corresponding standards and should have a quality certificate. c. Visually inspect the surface of the steel plates one by one. Defects such as cracks, pores, heavy skin, scabs, slag inclusions, scratches, surface scars, damage, etc. are not allowed. Penetrant testing and magnetic particle testing are used when visual inspection is difficult. d. After the edge plate bevel processing is completed, ultrasonic inspection should be carried out within 100m of the bevel side in accordance with the provisions of "Non-destructive Testing of Pressure Equipment" NB/T47013 according to the specification requirements. If it reaches the Level III standard, it is qualified. e. After using flame cutting bevel to remove the oxide layer, the bevel surface should be penetrated and evaluated according to the standards of BH/T47013. If it reaches level II, it is qualified. f. Semi-finished products that have been blanked and cut should be marked accordingly and the finished products should be protected to avoid mixing and misuse of materials. 2) Prefabrication and inspection of tank bottom plates (1) Before prefabrication of the bottom plate, layout drawings should be drawn according to the design drawings and comply with the following regulations: a. When cutting the tank bottom plate, the design diameter should be appropriately enlarged by 0.1%~0.2%. ； b. The minimum size of the edge plate along the radius of the tank bottom shall not be less than 700mm ； c The butt joints of arcuate edge plates should adopt unequal gaps. The outer gap is 6-7mm, and the inner gap should be 8-12mm. d. The width of the medium-sized board shall not be less than 1000mm ； The length shall not be less than 2000mm ； e. The distance between any adjacent welds on the bottom plate shall not be less than 300mm. f. The number of radiographic inspections of tank butt welds shall be carried out in accordance with the following requirements. g. The fillet welds at the bottom of the tank should be tested accordingly according to the requirements of GB/T50128-2014. After passing the test, all welds should be tested for tightness using the vacuum box method. The test negative pressure value should not be lower than 53Kpa. If there is no leakage, it is qualified. h. After the root pass of the lap joint weld of the overlapping portion of the three-layer steel plates at the bottom and the T-shaped weld of the butt tank bottom plate is welded, penetration testing should be carried out within a range of 200mm in each of the three directions. After all welding is completed, penetration testing or magnetic particle testing should be carried out. i. The radiographic flaw detection results shall not be lower than Class III standards. 4) Accessory installation and inspection. The allowable deviation of the center position of the opening pipe is 10 mm, and the allowable deviation of the extension length of the pipe is ±5 mm. ； The curvature of the opening reinforcement plate should be consistent with the tank body, and must ensure tight fit ； The sealing surface of the open-hole connecting pipe flange should be flat without welding burrs or scratches. The flange sealing surface should be perpendicular to the axis of the connecting pipe. The inclination should not be greater than 1% of the outer diameter of the flange and not larger than 3 mm. The bolt holes of the flange should be evenly distributed across the span. 5) Water filling test: Fresh water should be used for the water filling test, and the water temperature should not be lower than 5℃. Fill water to the design level indicated on the drawing and maintain it for 48 hours. If there is no leakage or abnormal deformation of the tank wall, it is qualified. 6) Painting quality standards and inspection methods