Foamy and flat beer are big issues for a lot of draft beer system owners. It's very frustrating to hook up a new keg and end up filling up your cup with creamy head or flat, lifeless beer instead of a perfectly poured beverage. The mistake a lot of people make is adjusting the output pressure to the keg when it may not be necessary. Improperly adjusting the pressure may temporarily mask the issue, but you may end up getting the keg out of balance which will result in foamy or flat beer toward the end of the keg that cannot be corrected with pressure adjustments (Click here to see our trick on ensuring your keg stays balanced).
A better solution is to adjust your flow rate. You can invest in a flow control faucet or you can adjust the length of your beer line to change the speed of your pour.
This video shows how the length of your beer line affects flow rate. It shows a kegerator with a five foot beer line on one side and a twenty foot beer line on the other. Both lines are attached to the same keg coupler with a Y-fitting, so they are being run at the exact same pressure. As you can see in the video, the added length of the twenty foot beer line slows the pour without having to adjust the pressure.
Professionals use varying lengths of 3/16" I.D. beer line to adjust flow rates on long draw systems. The longer line adds restriction, allowing you to increase pressure without making the liquid blast out of the faucet. This is great for beverages with a higher volume of CO2, such as hefeweizens, sours, carbonated water and soda.
The big take away is that the best way to speed up or slow down your pour is to decrease or increase the length of your beer line instead of adjusting the output pressure on your regulator.