Changes

Manufacturers of perforated pipe are often able to provide the open area per meter length:  

Manufacturers of perforated pipe are often able to provide the open area per meter length. Where this information is not directly available, the open area can be calculated by measuring the perforations and summing the open are per meter. The maximum flow rate through a perforated pipe (''Q_max'', L/s) may be calculated:  

<math>\frac{Q_{max, p}=L\times B\times C_{d}\times A_{o}\sqrt{2\cdot g\cdot \sum d}}{1000}</math>

<math>\frac{Q_{max, p}=L\times B\times C_{d}\times A_{o}\sqrt{2\cdot g\cdot \sum d}}{1000}</math>