Design of SF Double-Wall Tanks

We need to understand the following information.

I. Process and Medium Parameters

Medium Characteristics

• Medium name (e.g., crude oil, chemical solvents, acid-base solutions, etc.)
• Physical properties: Density, viscosity, flash point, boiling point, freezing point, vapor pressure
• Chemical properties: Corrosivity (pH value, corrosion rate), toxicity, flammability and explosiveness
• Temperature range: Storage temperature, maximum operating temperature, minimum ambient temperature

Storage Requirements

• Design capacity (effective volume, total volume)
• Storage cycle (single filling volume, turnover frequency)
• Filling factor (usually ≤ 0.9 to prevent overflow due to thermal expansion and contraction)
• Whether heating/cooling is required for the medium (temperature control range)

II. Structural Design Parameters

Tank Body Dimensions

• Diameter (inner diameter/outer diameter), height (total height, effective liquid level height)
• Head form (ellipsoidal, dished, conical) and dimensions
• Wall thickness (inner layer, outer layer, interlayer)

Material Selection

• Inner layer material: Carbon steel, stainless steel, FRP (Fiberglass Reinforced Plastic)
• Outer layer material: Carbon steel, stainless steel, concrete (selected based on corrosion environment)
• Interlayer filling: Thermal insulation materials (polyurethane, rock wool), insulation layer thickness

Structural Details

• Flange, manhole, and nozzle dimensions and positions
• Floating roof/internal floating roof design (if applicable)
• Support structure (vertical/horizontal, saddle/skirt support)

III. Safety and Performance Parameters

Safety Standards

• Pressure rating (atmospheric pressure/low pressure/high pressure)
• Sealing grade (leak prevention, corrosion resistance)
• Explosion-proof rating (for flammable and explosive media)
• Seismic rating (determined based on installation environment)

Detection and Monitoring

• Interlayer leak detection system (e.g., level sensors, alarm devices)
• Anti-corrosion coating thickness and type
• Strength calculation parameters (allowable stress, safety factor)

IV. Regulatory and Environmental Parameters

Compliance Requirements

• Applicable standards (e.g., API 650, GB 50074, ASME VIII)
• Certification requirements (pressure vessel certification, anti-corrosion certification)

Environmental Conditions

• Installation location (above-ground/underground/indoor/outdoor)
• Soil conditions (soil corrosivity consideration for underground tanks)
• Meteorological conditions (wind speed, temperature, humidity, seismic intensity)

V. Other Auxiliary Data

• Transportation and installation requirements (weight, size limitations)
• Maintenance cycle and inspection space
• Emergency response measures (leakage emergency plan, fire protection facilities)