Ok I got some Pics!!
So here this is a 3/4 inch nipple with a 1/2 inch nipple inserted into the 3/4. When the 3/4 nipple is threaded into the 1 to 3/4 bushing it locks it in place as NPT is a tapered thread. You can cut slits into the end of the 3/4 nipple to help compress and bite down if needed.
So here inside there is a step where the 1/2 inch nipple ( nozzle ) is inserted. So if the water drip is left on after a stall or shut down; it cant leak into the reactor. Orient one of the air intake holes in the cap down so it can drain out instead.