Originally Posted by Synovia
Thats the pressure release valve. They'll blow at about 70psi, IIRC. you probably had the regulator wide open.
Where did you get the regulator? usually they have instructions.
Synovia, thanks. You were exactly right, the regulator was turned way open. Weird, as I had it set to a steady 12 psi. My old tank was empty and I just unscrewed it and screwed the new one back on. I didn't even touch the pressure adjusting valve. You learn something new every day with this hobby.