plumbing the zero

[maple flats]

I am ready to plumb up the Zero vac tank. Should I run all vac thru the tank, or can one line hook to the dry line, which in turn hooks into the tank. My thought is to run my 2 x 3/4" mains into the tank and the dry line too. Then have the vac line connect to the dry line just above the tank. I'm thinking a manifold in likely 3" PVC and the vac line out the top side. Does this sound right? My Vac line from the pump will be 2" PVC. Or should all vac go into the tank and then hook each of the wet lines and the dry line to the tank? I am pulling both agitators off the tank, how do you guys with Zero tanks run PVC into the tank and seal the vacuum? I'm thinking of putting a fitting (for the shoulder) on top and a 2" (or 1.5 if necessary) down into the tank with some kind of sealing gasket.

[markct]

on top of my zero tank i welded a stainless pipe nipple to where the agitator used to sit and then made a manifold to put ontop and that is where all the lines come together, wet and dry lines all flow into it and the whole tank is under vac from the dipstick port

[maple flats]

That would be rather difficult, the tank is set up, in a cellar hole, about 40-45' away from where a welder could get his truck, are there any other methods?
Also, I started to remove the agitator motors and mix paddles yesterday, I figured taking the clamp off would do it. When I removed the clamp there is still something holding them together. I can't see it well enough to be sure but I think it is either 2 small opposing set screws or a small roll pin, I think it must be the latter. Anyone confirm that. I want to know if I need to drive it out or try to unscrew it. Thanks for any help.