specific thermal expansion tank recommendation?

[Kcodyjr]

This is going into my MH along with the existing 30gal electric tank (see my other thread for backstory) and a complete 3/4" copper repipe from the park's supply line up to my PEX branch lines. I could write a book about why, but suffice to say what's there is inadequate by every measure I know, and it has to be cut anyway to install new subflooring.

The first non-passive thing the supply will see when it comes out of the floor will be a regulator. Therefore, I think the 2.1 gallon tank should be sufficient. For space reasons, it would be most convenient to install it upside down, screwed directly atop the riser. The tee leading to the heater's inlet would be directly below that, then the vacuum relief valve, then a hose connection to a stub on the heater. The heater isolation valves will probably be at the bottom of the risers.

I'm having a hard time distinguishing between the Watts DET-5 and the apparently newer PLT series. My major concern is being sure it meets the newer CA/VT lead free standard, and the next concern is the fitting - if it's stainless, I need a dielectric union, right?

Any other suggestions relating to a more-or-less complete overhaul are welcome.

Don't worry, I've already lined up a licensed pro that's willing to review my work, pull the permit, and perform the actual installation.

 

[Kcodyjr]

Bad form replying to my own post, but I tracked it down. According to Watts' website, the DET series has "* Lead free models available" right next to where it says "obsolete product". The PLT series is AB1953 compliant.