Abstract: A pipe connection for plastic pipes particularly fiber reinforced synthetic pipes made of thermosetting resin, comprising a female pipe part with a widened end of which the inside tapers from the free end and adjoins a longitudinally extending recess in the inner wall of the female pipe, the male pipe part having a protruding part adapted to this recess and having a first end face that on its end adjoins a conical end face which is adapted to the conical shape of the inside of the aforementioned widening, and a glue layer extends from the inside of the pipe connection as far as the outside of the male pipe part. Preferably the protruding part consists of an inner, chemically resistant, layer of a fiber reinforced synthetic resin pipe, which on its outside carries a fiber reinforcement and the inner side of the conical widening has a greater inner circumference which is considerably greater than the outer circumference of the male pipe part.

Abstract: A plastic bag with zig zag plies provided with a tubular valve foil sealed on the one hand to an outwardly folded tubular foil part originally situated between two incisions along zig zag ply edges and on the other hand to an end seal of the tubular foil and at last to the tubular foil by a seal extending between the end points of the said incisions and said end seal.The plastic bag may be provided with an outer lining or covering bag for protecting the bag. The covering bag is provided with an opening for passage of the tubular valve foil.