[JRTJH]

You still have a few posts to go before you get told to "go to bed" LOL

As for the pic you posted, Yes that is the black tank anti siphon valve.

Here is a picture of "roughly" what the entire system looks like:

There are brass anti siphon valves available at Lowes or HD. you will probably have to do some rearranging of the PEX lines/fittings to connect the brass valve. Remember, you still need to winterize it as the fittings may still freeze and crack. The actual PEX tubing is pretty flexible and probably won't be damaged by freezing, but the fittings may not survive the winter.