Abstract: A coupling for vertical connection in sewage plumbing used in tall and high-rise buildings, is disclosed. The coupling is equipped in its inside walls with a pair of vortical blades for descending sewage streams from the upper floors into the coupling to impinge on their top blade surface to flow sideways into a spiral flow down the coupling. The more intense vortex streams developed, the faster the streams fall along the plumbing. For a vortex generates a vertical column of upwardly moving ventilative air in the center of the sewage streams, smoothing the descent of the drainage. Moreover, the top and bottom blades are mounted at different levels of height inside the coupling, and circumferentially displaced to each other so as to form a V-shape as seen in the horizonal projection view.