Design & SizingQuestion 2 of 110
Using the 0.408 velocity relationship v = 0.408 x Q / d^2 (v in ft/s, Q in gpm, d in inches inside diameter), what is the velocity of 18 gpm flowing in a pipe with a 1.00 in inside diameter?
a.3.7 ft/s
b.7.3 ft/s
c.10.2 ft/s
d.14.7 ft/s
Explanation
v = 0.408 x 18 / (1.00)^2 = 7.34 / 1.00 = 7.3 ft/s. Because d^2 = 1, the velocity equals 0.408 x Q directly. This sits just under the 8 ft/s limit commonly set for cold-water piping to control erosion and water hammer.
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