A manifold of a valve conducting gas or liquid has a passage with an inlet and at least one outlet. The passage changes direction from the manifold inlet to the manifold outlet over a length of the passage. The cross-section of the manifold in the region where the passage changes direction, merges in a plurality of sequential sectors from an almost round or oval cross-section over a plurality of cross-sections that are flattened on the inner manifold side again into an almost round or oval cross-section. In the region of the flattened cross-section of the passage, the cross-sectional contour has a plurality of arcuate sections that are continuous with one another.