Marsh-McBirney Flo-Mate 2000 - Calculate the Flow

2-2
Convert the Diameter to Feet and Square
D
2
= (Diameter in inches ÷ 12)
2
Where:
D
2
is in feet diameter squared. The diameter needs to be converted to feet because
the velocity is in feet per second.
Calculate the Flow
K x D
2
x = flow
Example:
What is the flow in millions of gallons per day (MGD) of a 10-inch diameter conduit with a 6-inch
level? The U has been calculated to be 1.5 ft/sec.
Calculate Level/Diameter Ratio L/D
Level ratio L/D = 6 inches/10 inches = 0.6
Identify K
K = 0.6 4 0.3180 from Table I
Calculate D
2
D
2
= (10 in ÷ 12)
2
= (0.833 ft)
2
= 0.694 ft
2
Calculate flow
K x D
2
x = MGD = 0.3180 x 0.694 ft
2
x 1.5 ft/sec = 0.331 MGD
U
U