scope:

The following structure and calculation rules apply to vertical, cylindrical, factory-fabricated fl at base thermoplastic tanks made from panels with a reinforced bottom section. The following prerequisites must be satisfi ed when using this supplement:

• Only one outer shell; double-shell eff ect

• The shells must be welded to one another and to the base in away that corresponds to one of the variants shown in Figure 1

• The base thickness is identical to the thickness of the bottomsection without outer shell

• The thickness of the outer shell is 0.5 to 1.0 times thethickness of the bottom section

• The outer shell with a height of h Z,0 is shrunk on to the bottom section with a height of h Z,n without gaps and without anyimpermissible pre-stressing

• The bottom section is at least 100 mm higher than the outer shell h Z,n h Z,0 + 100 mm

• The characteristic material values are identical for both shells

• No openings in the reinforced area