You need to factor in the length of run of your pipe and all the fitting (elbows, tees, valving, etc) to see if the resultant P-drop results in satisfactory supply pressure to whatever it is you are delivering the gas. Many appliances "expecct" a minimum supply gas pressure.
Consult the IFGC (International Fuel Gas Code) for quick and easy line size selections.
Flow of high pressure gas in standard wall pipe is usually accompanied by a considerable pressure drop and decrease of the density along the entire line. The flow is expressed by the equation: Q = d to the 8/3 power x the sq root of (P1 squared minus P2 squared), all divided by the square root of (Sa x L), then multiply the product of the division x 33.95
Q = Flow of free gas at 60 degrees F (cubic feet/min.)
d = Inside dia. of the pipe in inches
P1 = Initial pressure (psi absolute)
P2 = Final pressure (psi absolute)
Sa = Specific gravity of the gas (air = 1)
L = Effective length of the pipeline in feet