Design & SizingQuestion 6 of 110
A copper water line has 90 ft of straight pipe. Fittings add an equivalent length of 3 ft each for four elbows and 8 ft for one gate valve. What is the developed (equivalent) length used for friction-loss calculations?
a.98 ft
b.110 ft
c.122 ft
d.134 ft
Explanation
Developed length = straight pipe + fitting equivalents = 90 + (4 x 3) + 8 = 90 + 12 + 8 = 110 ft. Friction loss is calculated on this equivalent length, not on the measured pipe alone, because fittings behave like extra pipe. Ignoring fittings understates the loss and can undersize the pipe.
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