It only last for the few seconds it takes the new volume of gas to enter the keg to the set psi. Had this keg for 8 months and it just started. Pours good beer still.
same here I suspect it's the gas in tube since it only happens on some kegs and not all of mine. I never checked to see what tube is in which keg making the noise but I assume it would probably be the red plastic ones since they have a smaller diameter and the fast moving gas may cause a vibration in the tube?
One of mine does it when I pour 2ltr bottles off it.. I think a little flange or the spring on the poppet vibrate and push the sound down into the keg and it amplifies it... It only happens when the gas is moving fast tho..