correct propane tank wiring?

[Steve-W]

Here's my second thread in the electrical section

When I bought my truck it had already been converted to propane and I did a complete cab swap and bought a new 21 fuse EZ wire set.
Now I think I have the wiring figured out (thanks to member VetteVet) and it's time for the last piece of kit, the propane set up. Because I just ripped out the old wiring, I forgot how the electrical part for the propane tanks was set up.

I have two 16Gallon propane tanks and I have to switch between them because their not connected (I also have to fill them seperately)

I drew this Visio schematic, could any body tell me if this looks to be alright?
the safety relay is to cut of the feed after 1,5sec to the valve on the tank(s) so the propane doesn't flow when I bent the truck around a tree and the engine has stopped, but the ignition is still on.