I am trying to fix some pipes in my cabin that froze this winter. I need to replace some compression fittings. I tried to put a 5/8 inch OD compression fitting on the line. It was a little bit loose but I could not tighten it down. Is it possible I have 1/2 inch OD pipes? Where would I locate 1/2 inch OD to 5/8 inch OD reducers?