Humming regulator and foam

[bjacokes]

Sorry for another foam-related thread, but...

I've been having foam problems, with a keg @ 40F and 10psi. I had been using 5ft of 3/16 inch tubing and a picnic faucet at keg level, but after reading some advice here I just hooked up 8ft of 3/16 inch tubing instead. By all measurements, this beer should be coming out with no problems. Instead I end up with 3/4 of a glass of foam.

BUT, basically all of this foam is coming in the first second or two. If I line up two glasses side by side, I can pour half a glass of foam, and then move over to the second glass, which is filled perfectly. This isn't a priming issue - I have the lines in the fridge, and if I try this twice in a row the same thing will happen. So I have to imagine something is going wrong in the first second of pouring.

Now, I've always been a bit suspicious of my regulator. As it fills up my keg, there is almost a humming/rattling sound, even when I open the valve a little at a time. I'm not experienced enough to know if this is common, so I'm thinking maybe there is something wrong internally - perhaps there is some kind of resistance to the first couple ounces of flow which is causing all of this foam until it gets going?

I'm just wondering if this sounds familiar to anyone. I've been tinkering with my system for months, and the only thing that's helped is going to 5psi. The fact that it still messes up with 8ft of line means I need some help. Thanks!

 

[samc]

What happens if you turn off the gas, disconnect the QD from the corny? That should eliminate the regulator as any part of the problem. That would be my first step. If the keg is properly carbed at the correct psi and it does not pour right then maybe some kind of leak?

 

[david_42]

Most likely the temperature of the line is higher than that of the beer. Even though the line is in the fridge, if it is sitting on top of the keg, it will be warmer. Once the line is cooled off, the problem goes away. Before you pour, take a look at the line. Does it have beer or gas in it? If the answer is gas, the line is warm.

Most regulators are noisy.

 

[bjacokes]

I'm pretty sure it's not a temperature issue. Like I said, I can replicate this several times, so I would think the temperature of the line would have dropped after the first iteration.

The idea of unhooking the regulator is a great one. In fact, I was thinking about this today - there is so much gas in the headspace of a keg, and the volume of beer being dispensed is so small relative to that gas, that I imagine the flow of liquid would be unaffected by even moderately large fluctuations in the rate at which the regulator lets gas in.

Anyway, sure enough, I unhooked the gas disconnect and still got the same problem. I was able to lessen the problem by chilling the beer from 40F to 35F, but there is still a distinct spurt of foam at the beginning of the pour. The line stays entirely clear, but the picnic faucet is definitely dispensing foam for that split second. This might not matter much since I will soon be switching to a kegerator+faucet, but has anyone ever had trouble with plastic picnic faucets producing foam? The other problem I can potentially think of is that the regulator might be displaying too low of a PSI - is it possible to for regulator gauges to be off, and if so can they be calibrated at home?

Thanks again for all the help.