Stainless Steel Storage Tanks

Standards & Compliance

Our stainless steel storage tanks are designed, fabricated, and tested in strict accordance with international codes. Whether for high-pressure chemical processes or hygienic pharmaceutical applications, we ensure full compliance to guarantee safety, purity, and structural integrity.

1. Design & Fabrication Codes 

We manufacture tanks to meet the specific pressure, temperature, and hygiene requirements of your application:

2. Material Standards 

All raw materials are fully traceable and comply with international standards:

Austenitic Stainless Steel: ASTM A240 (Grade 304, 304L, 316L, 321).

Duplex Stainless Steel: ASTM A240 (Grade 2205, 2507) for highly corrosive chloride environments.

Sanitary Fittings & Flanges: 3-A compliant, Tri-Clamp (TC) connections.

3. Surface Finish & Hygiene Standards 

For food and pharmaceutical applications, surface roughness is critical:

Internal Finish: Mirror polished to Ra ≤ 0.4 μm (or Ra ≤ 0.8 μm), ensuring a crevice-free environment to prevent bacterial growth.

Passivation: ASTM A967 passivation treatment to restore the chromium oxide layer after welding, ensuring maximum corrosion resistance.

Weld Quality: TIG (Tungsten Inert Gas) welding for sanitary tanks to ensure smooth, oxidation-free internal welds.

4. Welding & Testing Standards 

Welding Procedures: Qualified under ASME Section IX (WPS/PQR).

Non-Destructive Testing (NDT): Radiographic Testing (RT), Ultrasonic Testing (UT), and PMI (Positive Material Identification).

Leak & Pressure Testing: Hydrostatic testing, pneumatic testing, and vacuum leak testing for jacketed tanks.

Third-Party Inspection: SGS, BV, TÜV, and Intertek are fully supported.

Materials & Surface Finish

Unlike carbon steel tanks that rely on internal coatings, stainless steel tanks provide inherent corrosion resistance and hygienic properties. We select premium stainless steel grades and apply precise surface treatments to meet the stringent requirements of your specific industry.

1. Base Material Grades 

We use certified stainless steel plates (ASTM A240) to ensure durability and chemical compatibility:

304 / 304L: The standard choice for general water storage, food and beverage processing, and mild chemical environments. Excellent formability and weldability.

316 / 316L: Contains molybdenum for superior resistance to chlorides (salt water) and aggressive chemicals. Ideal for pharmaceutical, marine, and chemical applications.

321: Titanium-stabilized grade, designed for high-temperature applications (up to 800°C) to prevent intergranular corrosion.

Duplex 2205 / 2507: High-strength, highly corrosion-resistant alloys used for severe environments (e.g., high-chloride chemical processing and desalination).

2. Internal Surface Finish 

The internal surface finish is crucial for preventing bacterial growth, scaling, and product contamination.

2B Mill Finish: Standard smooth finish for general industrial and water storage.

Pickled & Passivated: Removes welding heat tint and restores the chromium oxide layer (ASTM A967), ensuring maximum corrosion resistance.

Mirror Polished (Ra ≤ 0.4 μm): Mechanical polishing to a mirror-like finish. Essential for food, dairy, and pharmaceutical tanks to ensure a crevice-free, sterile environment.

3. External Surface Finish 

2B / BA Finish: Standard mill finish or bright annealed for a clean, industrial look.

Brushed / Satin Finish: Provides a uniform, scratch-resistant aesthetic finish.

Insulation: Available with Rock wool, Polyurethane (PU), or Aerogel, clad with stainless steel or aluminum jacketing for temperature maintenance and personnel protection.

Manufacturing Process

The reliability and hygiene of a stainless steel storage tank depend on precise fabrication and strict weld quality control. We follow a controlled manufacturing process—from raw material inspection to final passivation—to ensure the tank meets ASME, 3-A, and cGMP standards.

Step 1: Material Preparation & Cutting 

Material Verification: All stainless steel plates (304/316L) are tested via PMI (Positive Material Identification) to verify chemical composition.

CNC Cutting: Plates are precisely cut using CNC plasma or laser cutting to minimize heat distortion and ensure exact dimensions.

Step 2: Plate Rolling & Forming 

Cold Rolling: Heavy-duty rolling machines form the stainless steel plates into precise cylinders.

Edge Preparation: Plate edges are machined or ground to ensure a tight fit for welding, preventing oxidation gaps.

Step 3: Precision Welding 

Shell & Bottom Seams: For industrial tanks, we use Automatic Submerged Arc Welding (SAW) for deep penetration.

Sanitary Welds: For food and pharma tanks, we use TIG (Tungsten Inert Gas) welding with high-purity argon gas shielding. This ensures smooth, oxidation-free, and crevice-free weld beads (no undercuts or pinholes).

WPS/PQR: All welding procedures are qualified under ASME Section IX.

Step 4: Surface Treatment & Passivation 

Mechanical Polishing: For sanitary tanks, internal welds and surfaces are ground and mirror-polished to Ra ≤ 0.4 μm.

Pickling & Passivation: The entire tank undergoes pickling and passivation (ASTM A967) to remove welding heat tint and restore the chromium oxide layer, maximizing corrosion resistance.

Step 5: Non-Destructive Testing (NDT) 

Radiographic (RT) & Ultrasonic (UT) Testing: Performed on critical shell and bottom welds.

Dye Penetrant Testing (PT): Used on TIG-welded corners and nozzle connections.

Blue Point Test : Chemical test to confirm the passivation process is complete and the surface is fully protected.

Step 6: Hydrostatic & Leak Testing 

Hydrostatic Test: The tank is filled with water to test for structural integrity, weld tightness, and leak-proof performance. (For jacketed tanks, steam or pressure testing is applied to the jacket).

Step 7: Knock-Down (KD) Packing 

Disassembly: Large-capacity tanks are disassembled into shell sections, tops, and nozzles.

Packing: All components are wrapped in waterproof paper and PE film, securely bundled with steel strips, and protected by wooden frames for safe FCL ocean freight.

1. What is the difference between 304 and 316L stainless steel tanks?

304 / 304L: Suitable for general water storage, food and beverage processing, and mild chemical environments.

316 / 316L: Contains molybdenum, offering superior resistance to chlorides (salt water) and aggressive chemicals. Ideal for pharmaceutical, marine, and highly corrosive chemical applications.
We also supply Duplex 2205 for extreme chloride environments.

2. What does "Sanitary Design" mean for your tanks?
For food, beverage, and pharmaceutical applications, our sanitary tanks feature:

TIG Welding: Smooth, oxidation-free welds with no crevices or pinholes.

Mirror Polishing: Internal surfaces polished to Ra ≤ 0.4 μm to prevent bacterial growth and scaling.

3-A Compliance: Designed according to 3-A Sanitary Standards and cGMP requirements.

3. How do you ship large stainless steel tanks?

For large capacities, we ship the tanks in Knock-Down (KD) form (disassembled shell plates, top, nozzles, and components). This significantly reduces ocean freight costs. We provide detailed erection drawings, and our engineers can guide the on-site assembly if required.

4. Can you customize the tank with accessories like agitators, jackets, or level gauges?
Yes. We offer a complete turnkey solution, including:

Heating/cooling jackets (dimple or coil type).

Agitators and mixers.

Level gauges, manways, and customized nozzles.

Insulation (Rock wool or PU) with stainless steel jacketing.

5. What are your delivery time, payment terms, and packing details?

Delivery Time: 30–45 days, depending on order quantity and customization level.

Payment Terms: T/T, L/C, O/A, D/P.

Packing: Wrapped in waterproof paper and PE film, securely bundled with steel strips, and protected with wooden frames for FCL ocean freight.

6. What information do I need to provide for a quotation?
Please provide:

Capacity/Volume (m³).

Stored medium (e.g., milk, acid, WFI).

Design pressure and temperature.

Surface finish requirements (e.g., Mirror Polish Ra ≤ 0.4 μm).

Destination port.
Our engineering team will review your requirements and provide a prompt CIF/FOB quotation.