Flare to NPT for gas?

I'm figuring out the gas plumbing for my brew stand. Looking to mate two banjo burners to iron pipe. Here's the question: It seems 3/8 flare and 3/8 female pipe thread are thread compatible.

Can I use my regular orifice fittings (orifice x 3/8 flare) and attach them to 3/8 FPT, or do I need to buy orifices that use NPT threads?

 

Im not sure if in thinking about the same fittings as you however if you are referencing a 37* JIC flared fitting they typically call out the flare end as well as the male or female (in this case male) end opposite of the flare. To my Knowledge the flared is not a compatible thread with NPT.

i've attached a picture of a JIC flare / NPT Male to hopefully show what I tried to explain.

 

Yeah JIC flare and NPT fittings aren't compatible with each other, you definitely need an adapter of some sort. Here's a fitting thread chart I found a while ago that should help you out.