If you are using a gas blender, preferably you will use approximately 22 PSIG to propel the beer out of the keg. To acquire a descent flow speed, you will require the identical amount of back pressure in PSI against the beer.
This back pressure is referred to as restriction. It comes from three areas in a system - hardware, gravity, and beer line. To assist you in building this system correctly, we will need to know what type of tower you will be utilizing, hardware used in the keg cooler, vertical distance between the faucet and the bottom of the keg, and the inside diameter, length and type of material of your trunk line you are using. Please advise.
Scott Zuhse, Instructor
Micro Matic Dispense Institute