I have a problem keg that has the end of the dip tube turning and the opening is flush with the bottom of the keg. This rotation only occurs with the final tightening of the fluid-out post--so I have to tighten it just enough to seal it, but not enough to rotate the dip tube and block the outflow. When rotated, the result is very much like when you hold your hand right in front of the vacuum cleaner attachment--the flow shuts down real fast, and you're lucky to get a half an ounce out.