Hydraulic grade line

Mather, J., Draw Some Help from Hydraulic Grade Lines, Chem. Eng. Prog., vol. 86, no. 10, 1990, p. 50. 

The term 144 PJp is called the hydraulic grade line [2], In a fluid flowing in a horizontal straight pipe, if the pressure is measured at both... 

Second, the friction loss hL from pipe entrance to exit may also be expressed as foot-pounds per pound of flowing fluid. This term is more commonly referred to as the head loss in feet of fluid. It is loss, because the hydraulic grade line shown in Fig. 6.1 exhibits the hL loss. 

Having introduced f, the objective is now to find a convenient analogy with which we may calculate any/factor. But first, how is this factor to be applied Why not just use the simple term hL and be done In answer, the hL factor, if reviewed in Fig. 6.1, is actually a part of the hydraulic grade line factor 144 Pi/p. Thus, the correct thing to do here is to put it in this factor. In all equation relationships of fluid flow problem solving, this is done. This simply says that/represents the flow of fluid losses due to friction inside pipe in all equations used. 

Hydraulic grade line Graphic representation of the mechanical energy equation as hydraulic or pressure head against length slope is frictional head loss per unit length. 

FIGURE 4 Illustration of hydraulic grade line concept. 

FIGURE 7 Ground profile (GP) plot showing initial hydraulic grade lines (HGLs) for pipes of different diameter. Eight- and 10-in. pipes (HGL8, HGL-iq) require additional control point static correction (CPSC) to clear the control point. 

TABLE I Sample Design Problem Illustrating Hydraulic Grade Line Method... 

FIGURE 8 Hydraulic grade line (HGL) method design for pipe flow problem showing placement of pumping stations and change of diameter of pipe to handle excess head downstream of control point. 

Fig. 6. The relationship between the hydraulic grade line slope and the mean flow velocity. Field experiments,...

The energy grade is the sum of the hydraulic grade and the velocity head and represents the height that a column of water would raise in a pitot tube. When plotted in a profile, this is referred to as the energy grade line, or EGL (see Figure 3.1). 

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