Water Flow Rate Units

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Water Flow Rate Units

• Volume / Time
• Cubic Feet Per Second (CFS)
• Gallons / Minute (GPM)
• Acre-inch / hour
• Miners Inch - used in the western US

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Water Flow Rate Measurement in a Channel Weir
Method
3
V-Notch Weir
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Water Flow Rate Measurement in a Channel Float
Method
V (L / T)(C) C 0.8
A dSh Q A V
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Water Flow Rate Measurement in a Channel
Slope-Area Method
Measure S, A, R, estimate n
A dSh Q A V
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Water Flow Rate Measurement in a Pipe Impeller
Meter
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Water Flow Rate Measurement in a Channel Parshall
Flume
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Water Flow Rate Measurement in a Channel Parshall
Flume
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Water Flow Rate Measurement in a Pipe Orifice
Meter
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Water Flow Rate Measurement in a Pipe Orifice
Meter
a is the pipe area in square feet h is the head
on the orifice in feet g 32.2 ft / sec2 C
0.6 for most orifices
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Water Flow Rate Measurement in a Pipe Orifice
Meter
Example 3-inch dia. orifice with a head of
2-feet. Find Q
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Water Flow Rate Measurement in a Pipe Orifice
Meter