BeerBorg

Well warm, really. My dark beers that is. I am going to be kegging my robust porter in two days and was wondering what is the highest temperature I can keep the beer at in the keg? I normally drink my dark beers at 50-55 degrees. Could I keep the keg close to 50 and still have it hold carbonation?

Yes it will just take more pressure. It appears you would need 13 to 21lbs of pressure on the beer.
http://www.kegerators.com/carbonation-table.php

You can force carb at that temp. but won't it pour foamy? I thought the warmer the beer, the easier it released the carbonation.

Thanks Gymrat, that's the chart I was looking for! And good question mtsoxfan, I would like to know the answer to that as well, I am still fairly new to kegging

You'll need a long beer line to counter the higher pressure. The beer lines provide resistance which slows the beer going through it, which in turn keeps the CO2 in the beer.
If you have short beer lines, you'll pour nothing but foam at higher pressure.

Depending on the PSI you decide to go with (to hit your desired carb level) you may need 12 foot or longer lines. It's not a big deal, just coil them up and zip tie them to the handle and they won't get in your way. There are calculators for beer line but from what I can tell they all suck.

What carb level are you shooting for? If you are pushing the 2.5 volumes or close to it you'll be near 21 psi and I would go with 15 feet of beer line to start. See how that goes and then chop off a foot each time if it is too slow or not giving you the results you want. You can always cut it shorter, but adding on - well.........

And the cost for beer line is cheap so the extra feet isn't going to break the bank.

Another option is to simply carb it very lightly like a British cask ale, and drink your porter the way it was intended by the folks across the pond.

I think I may just keep it at 40 degrees and set the carb level to reach something like 1.8-2.0 vol so it has a low level of carbonation. Looks like that would be about 7 psi. Then after I pour it I will just be patient to let it warm up in the glass a bit!