Sewers pipe sizing

On the smaller sizes of sewer pipe, of which there are literally thousands of miles and millions of joints in the United States, very small grout quantities (2 to 5 gal) are generally sufficient to seal a leaking joint. Gel times normally used are very fast, 10 to 30 sec, so that in a minute or two after pumping has stopped, the packer can be deflated and the treated joint examined with the TV camera to ensure that the grouting was successful. 

Rain water runoff may constitute the largest flow quantity collected in a drainage area and may be the governing factor in the sizing of the sewer pipes. 

The minimum size of underground sewer pipe, branch or drain hub should be 4 inches. 

The minimum size of sewer pipe in any curbed or diked area should be 8 inches. 

Figure 8-9. Capacity of sewer pipes running 3/4 full. Sizes 4-inch to 24-inch inclusive. Turbulent flow e = 0.00085. Darcy formula Q = 19.65 fh[5"...

The relative importance of the biofilm compared with the bulk water transformations of the wastewater is not just a question of flow conditions in terms of a daily variation. It is possible in the design phase of the sewer network to control the contribution of the biofilm by selecting a different — smaller — size pipe. 

From this specification it will be evident that the pipe itself, if it conforms to the specification, will be adequate in strength for gravity and low pressure waste handling, and that it is now available in sizes from 4 to 42 in. internal diameter. There are, however, three limitations that the buyer, if he plans to use the pipe in nonleaking industrial sewers, must bear in mind. In this specification ... 

When gas-trap manholes are used to sectionalize tnmk sewers, it is usually impractical to elbow the incoming line because of the larger size piping. Such is the case in Figure 8-7. The gas-trap manhole is an effective device for preventing backup of vapors from the tnmk sewer into branch systems. 

Concrete pipe, which is commonly used in oily and storm water sewer systems in sizes of 15 in and larger, is illastrated in Exhibit 13-40, Use of cast iron pipe smaller than 15 in is determined by economics. 

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