Stainless Steel Storage Tank Technical Parameters
1.Material Standards
Main Materials:
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o 304/304L: General purpose, resists weak corrosion (nitric acid, organic acids), temperature range -196~400°C
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o 316/316L: Contains Mo (2.5%), resists chloride corrosion, suitable for food/pharmaceutical industries
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o 321: Contains Ti, resists intergranular corrosion, suitable for high temperatures (≤800°C)
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o Duplex 2205: High strength, resists chloride stress corrosion, suitable for marine environments
Surface Treatment:
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o Mechanical Polishing: Ra≤0.4μm (mirror finish), meets GMP clean requirements
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o Electropolishing: Ra≤0.2μm, for ultra-clean applications
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o Sandblasting: Ra=0.8~1.6μm, for industrial environments
2.Pressure Ratings
| Type | Design Pressure Range | Applicable Standard | Typical Structure |
| Atmospheric | -0.5~+0.5 kPa | API 650 | Cone roof/flat roof |
| Low Pressure | -0.5~+10 kPa | ASME Section VIII Div.1 | Dome roof/jacketed |
| Pressure Vessel | 0.1~2.5 Mpa | ASME VIII Div.1 | Elliptical head |
| Vacuum Tank | Full vacuum~-0.1 Mpa | EN 13445 | Stiffening ring design |
3.Wall Thickness Calculation
Formula (ASME VIII Div.1):
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Cylinder thickness t = (P × R) / (S × E - 0.6P) + C
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o P: Design pressure (Mpa)
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o R: Inner radius (mm)
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o S: Allowable stress (e.g., 304L@150°C=129 Mpa)
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o E: Weld joint efficiency (0.85~1.0)
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o C: Corrosion allowance (0~3 mm)
Typical Wall Thickness Reference (Vertical Tanks):
| Volume (m³) | Atmospheric Thickness (mm) | 0.5 Mpa Thickness (mm) |
| 5 | 3~4 | 6~8 |
| 20 | 4~5 | 8~10 |
| 50 | 5~6 | 10~12 |
| 100 | 6~8 | 12~16 |
4.Functional Configurations
Heat Transfer Structures:
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o Jacket Types: Half-pipe jacket (pressure ≤2.5 Mpa), full jacket (pressure ≤0.6 Mpa)
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o Coil Types: Internal spiral coil (heat transfer area 0.5~50 m²)
Agitation Systems:
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o Top-Entry Agitator: Power 0.75~55 kW, speed 50~300 rpm
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o Side Agitator: For high-viscosity materials (viscosity ≤50,000 cP)
Instrument Interfaces:
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o Level Gauges: Radar type (accuracy ±1mm), magnetic flap (visible range)
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o Temperature Probes: PT100 (accuracy ±0.1°C)
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o Pressure/Vacuum Relief Valves: Pressure setting range -0.5~+1.5 kPa
5.Special Design Options
Sanitary Design (3-A/BPE Standards):
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o Internal radius R≥10mm, dead-leg free design
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o Quick-opening manways (DN400~500), CIP/SIP capability
Corrosion Enhancement:
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o PTFE lining/Halar coating (resists strong acids)
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o Cathodic protection (for seawater tanks)
Insulation Structure:
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o Polyurethane foam (thickness 50~100mm), stainless steel outer cladding
6. Quality Control
Non-Destructive Testing:
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o Radiographic testing (RT): 100% testing of butt welds
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o Penetrant testing (PT): Testing of all surface welds
Certifications:
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o Material Certificates: EN 10204 3.1
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o Pressure Vessel Certifications: ASME U Stamp/PED CE Mark
7.Selection Process
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1.Determine medium properties (corrosiveness, viscosity, solid content)
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2.Calculate volume and operating conditions (temperature, pressure, turnover frequency)
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3.Select material and surface finish grade
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4.Determine additional functions (agitation, heat transfer, etc.)
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5.Verify installation conditions (vertical/horizontal, support method)
Stainless steel storage tanks require custom design based on specific operating conditions. It is recommended to provide detailed process parameters to professional manufacturers WUXI YITENG for engineering calculations.