I'd want to replumb that whole thing anyway to get rid of those old style gate valves that like to leak and not shut totaly off at some point and switch to ball valves.
And if those are galv. unions they need to go also.
One way would be to install the two plastic pieces to the softener, add two slip to MPT (male pipe threaded) adaptors to the supply lines and make the connection using two flex lines in a loop.
And if those are galv. unions they need to go also.
One way would be to install the two plastic pieces to the softener, add two slip to MPT (male pipe threaded) adaptors to the supply lines and make the connection using two flex lines in a loop.