Stainless Steel Adapter, 3/8-18 Female NPT To 3/4-16 Male JIC 37 deg Flare, 90 deg Elbow

Thread-wise, it is set up exactly that way: one side is 3/8-18 female NPT, and the other side is 3/4-16 male JIC with a 37 degree flare seat. It is a 90 degree elbow, so it changes direction at a right angle instead of staying straight.

For that exact situation, the 90-degree elbow geometry on this adapter is what you'd want. One end threads into a 3/8-18 female NPT port, and the other end gives you a 3/4-16 male JIC 37-degree flare to connect your line to. The right-angle body lets you redirect the hose or tube cleanly without fighting for clearance. It's built from 316 stainless, so it handles the kind of environments where a standard carbon steel fitting wouldn't last.