Fuel Gas includes Natural, manufactured or liquefied petroleum. Natural gas (NG) normally will be supplied from the Utility Company’s street main lines, but liquefied petroleum (LP) gas will supply in an installed tank in property or in portable cylinders.
The energy value in 1 cubic foot of natural gas at atmospheric pressure is called “heating value”. The gas flow is measured in a cubic feet per hour (CFH). The gas heating value varies from 900 to 1100 Btu/cubic foot. Natural gas is nominally rated at 1000 Btu/cubic foot (CFH).
Gas service is usually low pressure (0.5 psi or less), or medium pressure (above 0.5 psi and up to 5 psi).
A. Principles of design
B. Gas piping system criteria
DL= 1.25 x L
C. Pipe sizing
Piping from the street main to the meter is usually sized by the Utility Company. Plumbing engineer is responsible for sizing the piping from the meter to the users.