Saw this idea over on hd by "chickenfeet" and thought i would copy it's my rough prototype...
it's brass / teflon free
stainless bolt inside a bit of 1/4 inch tube. Bolt cuts it's own thread and seems to seal against low air pressure
1/4 tube has a hole in the side to allow flow from offtake tube
hoping to test a bit later tonight on the end of a run i am doing... :)