I have two more like this with the 1/2" thickwall polycarbonate and 3/8 Male pipe threads:
I also have the 1/2" tube with 3/8 NPT with Orings and Half coupling if you wanted to go weldless. I haven't tested this out though so I'm willing to give someone a deal. Test it out. If it leaks, you an have the half coupling welded in and you're golden.
This reverses it, 3/8" tube to 1/2" NPT.