I think Sportsways used the 1/2" NPS straight pipe thread with O-ring for a long time.
I have never seen a 3/4" NPS Sportsways valve, but my understanding is that they did make them. All the Sportsways valves I have seen are the 1/2" straight threads. Rob got two tanks from me with that type of valve; one has the New England Divers logo on the valve, but was made by Sportsways.
There were a few White Stag valves with the 1/2" straight pipe threads also, but not for long.
I have never seen a 3/4" NPS Sportsways valve, but my understanding is that they did make them. All the Sportsways valves I have seen are the 1/2" straight threads. Rob got two tanks from me with that type of valve; one has the New England Divers logo on the valve, but was made by Sportsways.
There were a few White Stag valves with the 1/2" straight pipe threads also, but not for long.