Plumbing dual tanks and dual compressors

[ugotd8]

Hi all, So I've read thru this thread and I'm still not understanding.

I have a working setup and want to add another tank for more capacity. I want to do it with buying as few parts as possible (I.E. run one pressure switch, minimum tees, etc).

If you knowledgeable folks could look at the following four diagrams and let me know which one will work without the second tank exploding, I'd really appreciate it.

Diagram 1:


Diagram 2:


Diagram 3:


Diagram 4: