the pressure pipe portion 10 can also be provided as an independent portion which is welded into the train of the relatively long pressure pipe the pressure pipe portion 10 has diametrically opposing flanges 11 and 12 radially directed towards the outside which form a passage 14 or 15 respectively approximately slit shaped in cross section the shaping of the flanges 11 12 and the further parts respectively that are associated to the passages 14 and 15 respectively emerge more clearly from the fig6 and 7 in fig7 a flange body 34 can be recognised with an outer flange 32 which is screwed against the wall of the pressure pipe portion 10 at the outside with the aid of screws 33 as can be recognised in fig3 in particular the pressure pipe portion 10 is reinforced towards the inside in this region by a thickening 37 when u201c inside u201d and u201c outside u201d are mentioned above and below this refers to the pressure pipe i e to its interior or exterior respectively the flange body 34 features a sleeve portion 30 a which is introduced into the passage 15 the perimeter of the sleeve portion 30 which is longitudinal perpendicularly to the drawing plane is shaped corresponding to the cross section of the passage 15.