The frame of the tank is made of galvanized corrugated steel. Corrugation increases several times the rigidity of the frame. For example, a tank made of corrugated metal with a thickness of 1 mm in stiffness corresponds to a container made of “smooth” metal with a thickness of 4-5 mm.
Technical characteristics of steel
| Indicator | Unit | Value |
|---|---|---|
| Thickness | mm | 0,8-4 |
| Liquidity limit | N/mm2 | 350 |
| Strength limit | N/mm2 | 420 |
| Zinc coating | g/m2 | 275 |
| Sheet size (length, width) | mm | 3000х1150 |
The frame of each tank and bolted joints is calculated with a minimum margin of safety – 1.5. The average margin of safety is 2.
The corrugated sheets are connected with special screws that have a strength class of 8.8 and a special semicircular head. In addition to galvanizing, the screws are additionally cobalt coated. Since the screw is mainly in a humid environment, passivation of cobalt by an average of 5 years increases its service life.
Inside the frame, between the insert and galvanized sheets, as well as at the bottom of the tank a protective fabric is installed. High-density waterproof geotextile is used as a protective fabric. Geotextiles prevent friction and abrasion of the insert to the bottom or metal walls of the tank. The thickness of the geotextile is 1 mm.
Tanks are attached to the concrete base with special clamps. Clamps prevent the movement of the empty tank in strong winds and natural disasters.
