API 650 Standard Oil Storage Tanks

I. Basic Parameters (Tank Basic Attributes)

Tank Type and Dimensions

• Diameter (inside diameter / outside diameter), total height, effective height (maximum height for media storage);
• Head type (ellipsoidal, dished, conical, etc.), head height;
• Number of tanks (to be counted for multi-tank system design).

Design Standards

• Execution standards (e.g., API 650, GB 50128, ASME, etc.);
• Design pressure (positive pressure / negative pressure, 0 for atmospheric pressure tanks), design temperature (maximum / minimum media temperature).

II. Process Parameters (Media and Storage Requirements)

Media Characteristics

• Media name (e.g., crude oil, gasoline, chemicals, water, etc.);
• Media density (ρ), viscosity, flash point, corrosivity (presence of sulfur, acids, alkalis, etc.);
• Media volume (total volume, working volume, with safety margin reserved);
• Filling coefficient (maximum filling ratio for liquid media, e.g., 0.95, to prevent overflow due to thermal expansion).

Process Operation Requirements

• Inlet / outlet methods (top / bottom feeding, pumping / gravity discharge);
• Media temperature range (e.g., high temperature in summer, low temperature in winter);
• Whether mixing, heating / cooling systems (e.g., jacket, coil) are required.

III. Structural Parameters (Tank Body Design)

Tank Wall Structure

• Tank wall thickness (calculated per API 650, considering corrosion allowance);
• Tank wall section height, circumferential weld positions;
• Number and spacing of tank wall stiffeners (required for large tanks).

Support Structure

• Support type (skirt support, truss support, ground support);
• Skirt height, diameter, material;
• Foundation design parameters (ground bearing capacity, settlement requirements).

Accessory Parameters

• Manholes, nozzles (number, location, pipe diameter);
• Inlet and outlet pipes (media type, pipe diameter, pressure class);
• Safety accessories (safety valve, breather valve, level gauge, thermometer, drain outlet);
• Anti-corrosion coating thickness (e.g., epoxy coating, galvanized layer).

IV. Material Parameters (Material Selection)

Main Materials

• Materials for tank wall, tank bottom, and head (e.g., Q235B, 16MnR, 304 stainless steel, etc.);
• Material yield strength (σs), tensile strength (σb), elongation.

Welding Materials

• Electrode types (e.g., E4303, E5015), wire types;
• Welding process requirements (e.g., pre-welding preheating temperature, post-welding heat treatment).

Anti-corrosion Materials

• Anti-corrosion coating types (primer, topcoat), thickness;
• Cathodic protection system parameters (sacrificial anode, impressed current).

V. Environmental Parameters (External Conditions)

Geographic Environment

• Seismic intensity of the location (seismic fortification intensity);
• Wind load (maximum wind speed, wind pressure);
• Snow load (snow thickness);
• Soil type (e.g., silty soil, sandy soil), groundwater level.

Other Environmental Factors

• Corrosive environment (e.g., salt spray corrosion in coastal areas, atmospheric corrosion in industrial zones);
• Fire risk (proximity to ignition sources, fire protection distance requirements).