Changes

See also [[flow control]] and [[underdrains]].  

See also [[flow control]] and [[underdrains]].  

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 area per meter. The maximum flow rate through a perforated pipe (''Q_{max, pipe}'', m³/s) may be calculated as:  

 

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 area per meter. The maximum flow rate through a perforated pipe (''Q_{max, pipe}'', m³/s) is calculated similarly to [[flow through an orifice]]:  

<math>Q_{max, pipe}=L\times B\times C_{d}\times A_{o}\sqrt{2\cdot g\cdot h_{max}}</math>

<math>Q_{max, pipe}=L\times B\times C_{d}\times A_{o}\sqrt{2\cdot g\cdot h_{max}}</math>