I was trying to see if I could use NG vs propane. I have 25 feet of run of 3/4 gas line with medium pressure 2 lbs) which comes out to 1,800,000 BTU at the forge. If I use a 3 heads it would be splits between the 3 heads. I am a novice at forging but I can figure BTU. Any help would be great before I buy or build the forge