I took my Pentair Nautilus apart to clean it and found large cracks in the manifold. Last year I had small cracks that I sealed but obviously it is beyond that now. The part number on the manifold is 192220. I can't find this part anywhere. My local pool store says I need a 192193 (w/o Air Relief Extension) and the measurements look about right. This one has a air vent on it that my original does not have. I'm also finding 192173 which apparently has the air extension.
So the questions are.... Is the 192193 the correct replacement for me? What does the air relief extension do?
Thanks for any input.