Effects of Rifling on Four-Inch Pipe Transporting Solids

Tests to determine the effects of rifling installed in 4-in. pipe upon the transportation of mixtures of water and material are described in this paper. Results were compared with those from 2-in. pipe in an effort to discover any similarity between the transportation characteristics of each pipe such that the principle of these smaller pipes could be applied to larger pipe. Tests for the development of the optimum design of rifling for pipes in which sand was the transported material constituted the major part of the testing program. The rifling was tested later with silt, clay, and pea gravel used as the transported materials. An attempt is made to show that the results obtained through the study of 2-in. and 4-in. pipe can be extended to include pipes having a larger diameter; and further, that, under certain conditions, dredging technique of the present day can be improved considerably by the proper use of rifling in the discharge line.