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Piping System Friction
72 The Basic Tools
Figure 3.10 Friction loss in schedule 40 PVC and CPVC, IPS-OD. (Reprinted by permission
from “ Engineering & Specifications Manual,” IPEX, Inc., 2000.)
horsepower is increased due to the higher specific gravity; this will be
discussed in Chap. 6. The specific gravity of ethylene glycol–based
heat transfer solutions is provided in Fig. 2.5. For heat transfer
work, Fig. 2.7 provides specific heat data.
Care should be taken in selecting the percentage of glycol used in a
water system. This percentage should be such that the pumps never
operate near the freezing curve shown in Figs. 2.1 and 2.2. Slush can
form as the freezing temperature is approached, causing poor pump
performance.
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