Mini Design - Ideal Flow Rate for Small Systems
Most conventional beer taps are designed with 10mm diameter nozzle/spout so you can pour pint in just over 10sec.  This type of flow rate is great for high turnover bars and commercial venues but this high flow rate requirement is not not necessary or desirable for all applications.  For compact portable systems, or for home brew draft systems a slower flow rate is easier to control the flow and further reduces foaming issues due to the low liquid volume stored in the tap body.