California Pipe Flow Metering Method
Calculate the discharge from partially filled horizontal pipes discharging freely into the air using the California Pipe Flow Metering Method. This empirical method applies to pipes with internal diameters between 3-10 inches.
California Pipe Flow Metering Method
The discharge from the open end of partially filled horizontal pipes discharging freely into the air can be measured using the formula:
q = 8.69 (1 - a / d)^1.88 × d^2.48
Where:
- q = discharge (ft³/s)
- a = distance from the top of the inside surface of the pipe to the water surface (ft)
- d = internal diameter of pipe (ft)
This empirical equation is valid for pipes with internal diameters between 3-10 inches.
Unit Conversions
- 1 mm = 0.00328 feet
- 1 ft = 0.3048 m = 12 in = 30.48 cm = 304.8 mm
- 1 ft³/s = 0.0283168 m³/s = 101.9 m³/h = 28.32 dm³/s = 448.9 gal (US)/min