摘要 |
A double-walled or quadruple-walled foil bag (8) for receiving a liquid, more particularly beer, which is to be arranged in a preferably spherical pressure tank, consists of flat, superposed, circular or polygonal foil pieces (2a-2c) which are welded together at the edge. The foil pieces which form a foil bag half (8a, 8b) are provided in the central area with a connecting piece (5) which penetrates them. The foil pieces, which form the double or quadruple wall, are preferably cut out of a flattened, commercially available foil tube. In order to test the finished foil bag for imperviousness, only an annular peripheral area which runs next to the weld seam (6) and which is connected via a connecting channel with a central area surrounding the connecting piece (5) is inflated. The foil bag (8), which is to be introduced into a cover, is previously folded in the form of an umbrella so that the foil bag half (8b) which does not contain the connecting piece (5) is inserted into the foil bag half (8a) which contains the connecting piece (5). |