UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 852 



Contribution from the Bureau of Public Roads 

 Thos. H. MacDonald, Chief 



Washington, D. C. 



PROFESSIONAL PAPER 



October 28, 1920 



THE FLOW OF WATER IN CONCRETE PIPE. 



By Fred C. Scobey, Senior Irrigation Engineer, with discussion by Kenneth Allen, 

 Arthur S. Bent, F. C. Finkle, Allen Hazen, J. B. Lippincott, and H. D. 

 Newell. 



CONTENTS. 



Introduction : 1 



Nomenclature 2 



Types of pipe 3 



Part 1. Flow of water in pressure pipes 5 



Formulas for flow of water in concrete pres- 

 sure pipes 5 



Opinions of engineers regarding the carrying 



capacity of concrete pipe 9 



Necessary field data for determining the re- 

 tardation elements of various formulas. . . 12 



Scope of the experiments 13 



Equipment and methods employed for col- 

 lecting and inteqweting field data 13 



Elements of experiments for the determina- 

 tion of the friction losses in concretapipes . 20 



Page. 



Description of pipes 25 



Analysis of experimental data 45 



Effect of age upon carrying capacity 49 



Capacity of concrete pipes 51 



Estimate diagrams and tables; solution of typical 



pipe problems 54 



Comparison of various formulas 62 



Capacity of concrete pipe compared with that of 



wood-stave, cast-iron, or riveted-steel pipe. . . 65 



Part 2. Flow of water in grade line pipes 66 



Descriptions of pipes 71 



Conclusions 74 



Acknowledgments. 76 



Appendix „ 77 



Discussion 92 



INTRODUCTION. 



Consequent to the general increase in use of concrete during the past 15 

 years, it has been but natural that this material should be tried for 

 pipe lines; and, although there are localities where poor construction 

 has brought concrete pipe into disfavor, where properly made it is 

 undoubtedly a success. For a long thm concrete was thought 

 adaptable to low heads only. Now it is used extensively in this 

 country for heads exceeding even 100 feet, and in Europe lines have 

 been constructed to withstand pressure heads of several hundred feet. 

 Where the heads exceed more than 15 or 20 feet the pipe is, as a 

 rule, reinforced with steel. 



The fact that it may be made at or near the place of use recom- 

 mends this type of construction for irrigation or other pipes far 

 removed from railway lines. In many cases the forms and cement 



Note. — Tbis bulletin treats of tbe subject of flowing water in concrete pipes. It 

 is based on field tests made on pipes in commercial operation. Tbis publication is 

 offered for use of engineers designing and measuring concrete pipes for irrigation, 

 power, municipal, mining, or otber purposes and for courts and attorneys at law 

 interested in cases involving tbe carrying capacities of concrete pipes. 



164725°— 20— Bull. 852 1 



