foam in beer lines

[mrtickel]

Hi all im having a problem with my keg system and the kegs are from the last group buy.
When i keg my beer and its ready for drinking i hook up my beer lines and pull a pint through a beer tap that i got from a pub hear in town its a flow control tap as well, but when pulling a pint i get alot of foam and regulator is set to 5 psi and beer line is about 5 foot long going to tap and what i notice is there is foam building up in the beer line is this ment to be like that or show it be pure clear beer and no foam i have no leaks neither all line are tight and secure.
I have tried turning psi down and up iv tried the flow control on the tap and still the same thing alot of foam and feck all beer in the glass  .
anyone any ideas what could be the problem and the beer is not over carbed.

[Ciderhead]

What psi and how long did you carb the beer to start with?

[mrtickel]

i carbed the beer 12 psi for 10 days in my shed and its cold in my shed  temp. would be 10 degrees my be less.
The lines are clean

[fingalbrewer]

How is your setup cooled? The beer maybe colder in the keg or chiller and is warm8ng up in the line causing the co2 to come out of solution. Insulate your lines will help if this is the problem. You have flowcontrol so maybe shorten your line.