More about our Orifice equations
The Orifice Equation is originally derived from the following equation: Q = CA√(2gd)
To simplify the Orifice equation, use a coefficient of 0.67 and correct open area from square feet to square inches and depth of water from feet to inches.
- Q = Flow capacity (in cubic feet per second)
- C = Orifice coefficient
- A = Open area of grate (ft2 )
- g = Acceleration due to gravity (32.2ft/sec2 )
- d = Depth of water over grate (in feet)
We provide the flow capacity calculators to be used in theoretical calculations and are provided as a guidance only. There are many variables that occur in the field that are not taken into account. Please contact one of our Engineers with any questions you may have.