...
The advantage to designing a nonlinear CD is that higher chemical flow rates can be used. The limit of the current flow control module is 400 ml/min. This has been adequate for the currently operatings plants (La 34, Ojojona, Tamara, Marcala and Four communities). As the demand for larger AguaClara plants becomes an issue, larger chemical dose flow rates will be required. Furthermore, headloss through the orifice entering the flow control module increases as chemical flow rate increases. This requires the chemical stock tank to be elevated to an unreasonable height.
...
To reduce headloss through the flow control module orifice, a new flow controller is being used in the design. The module being used is a PT 75 LS Kerick Valve. This valve was chosen to minimize flow control module size and maximize orifice area.