With a union, and a couple of male threaded adapters soldered in place, no soldering will be needed whenever the valve needs to be replaced again.
I have second, and third owners of houses I sold over 35 years ago stop by my house and thank me, every so often for such planning. Most of them have to drive past my house to get to their lake house, which are all close to our house. One even gave us a 100 dollar gift card to a local restaurant for leaving a conduit from the road into the basement utility room with a pulling line in it.