Pressures in Manifold Pipes

Abstract

The effect of the momentum of the water on the pressures and flow in manifold pipes and in perforated pipe underdrains used in rapid sand filters, has long engaged the attention of designers. Mr. J. W. Ellms recently4 presented a paper giving the results of experiments on perforated pipes and stating rules for design. An extreme case of the variation of pressure and discharge from a manifold pipe is shown in figure 1, which is from a photograph taken in the Hydraulics Laboratory of the University of Illinois. A diagrammatic sketch of the arrangement used is shown in figure 2. Ten 2-inch pipes, each 36 inches long, are connected to a manifold pipe lined with cement to make its inside diameter 2 inches. On the ends