Andrew thanks for the site it is great! hurting my brain thinking so much after a day at work and now my 3rd pot but hey i gotta nutt this out!
Ok looks like your "Equilibrium Pressure" gives you your volumes of carbonation, lets say you want 2.5.
now temp dependent we assume that 14psi gives you 2.5 volumes. however this you need to add pressure to overcome the line resistance etc so you may up the pressure to 16psi.
This is fine while you are serving (2lbs over the vertical rise and keg resistance) but when you stop pouring the beer sits at 16 psi, so the volumes of carbonation grow over night to the "new" value....
This i gather is when the next time you pour, the beer (at the exit of the tap) is lower than the volumes of carbonation so in order to overcome the "loss" it has a negative pressure and hence the foaming as CO2 comes out of solution... a increase in tap temp will dramaticly increase this.
How can this be overcome? well in my mind it looks like you want the beer to sit at 14psi, then when you are about to pour it jumps to 16psi, when you finish the pour back to 14.
Now with such a small difference in pressure the beer will take a long time to "take in" the extra carbonation so you could have it at 14 over night and up to 16 when your drinking and turn it back down when you are finished...
All the above then (say 14psi) needs to be tuned to the line size and length
hence why i normally get froth the first time i pull the tap, be it cold or otherwise
