How is an air separator normally plumbed in? The one I have been looking at has 2 pipes coming in at the bottom, one from the flow the other to the pump, another pipe goes from the top to the cold feed, in the flow side there is a 'T' up to the vent. However I think I have seen them with the 'T' going to the cold feed and the top pipe going to the vent. Can anybody enlighten me.