The innovation of a bolt solved the century-old leakage problem of welded water tanks

Bolted stainless steel water tanks, which require no welding and can be assembled on-site, are rapidly replacing traditional welded water tanks in industrial and residential water supply systems. These tanks not only eliminate the risk of secondary water contamination caused by welding, but also open up new possibilities for ultra-large water storage capacity through their modular design.

What is a bolted stainless steel water tank?

The stainless steel bolt water tank is also called assembled water tank or modular water tank. Its core breakthrough is to abandon the welding process and adopt stamped standard modules (1m×1m or 1m×0.5m) to be assembled on site with high-strength bolts and EPDM sealing strips. Its composite plate structure is particularly unique:

• Three-layer composite panels: The outer layer is 3mm hot-dip galvanized steel (corrosion-resistant), the inner layer is 0.4mm SUS304 or 316 food-grade stainless steel (to ensure water safety), and the center is formed using a special pressing process.
• Pure stainless steel panels: 304 or 316 stainless steel panels are also available for certain scenarios. They are suitable for environments with a chloride ion content of 250ppm or less.

This structure not only retains the metal strength, but also eliminates the intergranular corrosion of the material caused by welding, and its service life can reach more than 30 years.

Why do engineers prefer bolted water tanks?

1.Zero welding, double guarantee of water quality safety

Conventional welded water tanks, when welded at high temperatures, can damage the surface oxide layer of the stainless steel, causing rust to easily form in the weld area. These tanks are also only suitable for water with a chloride ion concentration of 50 ppm or less. Bolted connections, on the other hand, achieve a seal through physical tightening combined with compression from a sealing strip, eliminating any heat-affected zone and preventing rust from seeping into the water.

Assembly efficiency increased by 60%, supporting dynamic expansion

A 1000m³ water tank can be assembled within 3 days:

• Bottom Plate Positioning: First, lay the bottom plate modules with sealing strips. Tighten the bolts in three or four crosswise steps (do not tighten all at once to prevent cracking).
• Vertical Side Panel Assembly: Install the wall panels layer by layer according to the number, ensuring a 90-degree angle with the bottom plate. Leave a 4mm gap between the vertical bolts before tightening the horizontal joints.
• Top Plate and Openings: Finally, install the manhole cover and pipe flanges (the overflow pipe requires an insect screen, and the outlet pipe must be elevated above the bottom of the tank).

Future expansion requires only removing some modules to add new panels, without having to replace the entire tank.

Maintenance costs reduced by 90%

If the sealing strips age after a few years of use, they can be partially disassembled and replaced. However, if the welded water tank leaks, it needs to be repaired with argon arc welding, which is expensive and may cause secondary pollution.

Typical application scenarios: from firefighting to food storage

Application Areas	Configuration Plan	Case Advantages
Rooftop domestic cold water tank	Pure 304 stainless steel plate + rubber and plastic insulation	Prevent freezing and cracking in winter, water quality reaches food grade
Pharmaceutical and chemical liquid storage tanks	316L stainless steel + insulation	Acid and alkali resistant, temperature fluctuation ≤2℃/24h
Solar system insulation water tank	Composite board + 50mm polyurethane foam	Heat loss rate <3%
Underground fire water tank	Composite board + polyurethane insulation layer	Save ground space and resist soil corrosion

Note: For water tanks larger than 50m³, it is recommended to design them in compartments. For water tanks with a height of more than 1.5m, a ladder must be installed.

Installation pitfall avoidance guide: foundation error determines success or failure

Bolted water tanks have strict requirements on foundation flatness. The concrete foundation must meet the following requirements:

• Flatness: Height difference <5mm (exceeding this will result in uneven stress on the bottom plate and water leakage);
• Channel steel beam spacing: Accurate to 100cm, beam height >50cm, diagonal error after welding ≤0.5cm;
• Insulation: Rubber pads must be placed between the channel steel and the water tank bottom plate to prevent electrochemical corrosion of the metal.

The essence of technology is not to replace, but to reshape possibilities

When bolts replace welding guns, the water tank changes from a static container to a growing and perceptible living system - this is not only a technological evolution, but also a reconstruction of the relationship between space and water.