Page 77 - HVAC Pump Handbook

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Piping System Friction
74 The Basic Tools

Figure 3.11 Friction loss in schedule 80 PVC and CPVC, IPS-OD. (Reprinted by permis-
sion from “Engineering & Specifications Manual,” IPEX, Inc., 2000.)

representation of Bernoulli’s theorem. The vertical dimension of these
diagrams is to scale and is shown normally in feet of head (see Eq. 4.1
for computing feet of head from known pressures and temperatures).
The horizontal dimension is not to scale and is used to separate the
specific changes in static and friction losses in various parts of the
system.
Pump head is usually shown vertically upward, while friction losses
can be shown vertically downward or diagonally. Computer programs
are now being evaluated to facilitate the development of diagrams
similar to those shown here.

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