Sizing natural gas pipes using black iron, a few questions:
1) Do I understand correctly that the usual residential system has a
pressure of 7" water column at the regulator, and the pipe system
should be designed so that when all appliances are running at
maximum demand, the pressure drop at any outlet should be less than
0.5" water column?
2) If I understand correctly, the pressure drop can be accurately
determined using the standard charts giving pressure drop/foot for
a given pipe size and diameter. How are fittings handled? One
source I read suggested treating any 90 or 45 degree fitting as 1.3
feet equivalent. Any drop on the through path of a tee?