17+ Natural Gas Btu Natural Gas Gas Pipe Sizing Chart US. For natural gas the nominal btu/ft3 varies from about 900 to 1100 btu/ft3. Example of a pipe system for a residential home.
Typical natural gas & low pressure propane installation.
If the plates are not available or you just want a good estimate use the appliance chart at the bottom of this. Natural gas pipe line sizing chart. Pipe sizing charts tables energy models. I ask because a good friend and neighbor of mine says the 1.25 is overkill for the volume required.