Foaming

[sg1009]

What temperature is your keg at? I've got a similar setup and the only thing that solves it is getting the beer down to <5 degrees or putting less gas in it.
Imagine it was a bottle of beer at that CO2 level, if you didn't chill it in the fridge it'd hit the roof with foam.

 

[Braindead]

The kegs are just outside behind the bar so the temp fluctuates.
Maybe it is down to CO2 pressure when the kegs full.
But the foaming calmed down when the weather was hotter last week so I dont think the outdoor temp is the issue.
I have a new brew ready to keg in a week, ill run some tests again