I have a Prochem Performer Plus and the discharge ball valve for waste tank leaks. I took it apart and it appears o rings are wasted. I have tried going to napa to match and came close, but to thick. Where can I get these o rings? and what exactly would I call them for the ball valve? I would like to replace full ball valve but it does not look like it comes out, or unscrews. Anybody have any ideas for me? It also looks like they were siliconed in which seems weird?