FIELD: metallurgy.
SUBSTANCE: invention relates to the tank made from the single-layer metal strip bent in the form of helix (20; 20.1, 20.2). In the upper or lower edge area of the metal strip the first, extending along the helix, edge section (22) of the metal strip, through passing along the helix bent edge (24) with the bent area (B) is bent toward the outer side(A) of the tank in the form of the cantilever flange. In the upper or lower edge area of the metal strip, there is the second extending along the helix edge section (26), and passing along the helix, consistently adjacent at height the edge areas of the metal strip which are tightly connected to each other by the continuous passing along the helix welding joint (40). The second edge section (26) of the metal strip extends along a straight line in the plane (E) of the metal strip. The welding joint (40) has the first and the second welding joint (42, 44). The first, preferably made initially, welding joint (42) is alloyed from the outer side (A) of the tank (10) with the outer wall of the second edge section (26) and with the wall of the bent area (B). The second, preferably manufactured afterwards, welding joint (44) is alloyed from the inner side with the end surface (30) of the second edge section (26) of the metal strip. The roots of the first and the second welding joint (42, 44) are alloyed with each other, so that there is the uniform through penetration welding joint (40), extending from the outer side (A) to the inner side.
EFFECT: tightness for a long period of time.
11 cl, 4 dwg
