Hello,to all of you helpers. Well here is what I need to know,. I am putting in my first pressure tank, it is one of those that the water and the air are all togeather, anyway,it has a outlet on it to put a float type air volume control for submresible pump, which is what I have. my question is,do I still have to put a pressure switch and check valve on it two. The reason for this confusion is, the book says, If air volume control not installedin this fitting,opening must be pluged using a male threaded plug of prper size. then below this it says,,Optional.. must be installed if pump does not have pressure switch or does not have a check valve, so I was wondering if I just need the air volume control? any help is greatly needed,,,thank you,,Indy