### Natural Gas Pipeline - Friction Factor

**Steel Pipe Dimensions **

**PE Pipe Dimensions **

**Gas Data**

**Friction Factor**

**Friction Factor - Colebrook**

Friction factor calculated for pipe roughness and Reynolds number; most popular equation for general gas transmission pipelines.

**Friction Factor - Modified Colebrook**

Modified Colebrook equation based on US Bureau of Mines experiments; gives higher pressure drop compared to original Colebrook equation.

**Friction Factor - Weymouth**

Does not consider pipe roughness; uses an efficiency factor used for high-pressure gas gathering systems; most conservative equation that gives highest pressure drop for given flow rate.

**Friction Factor - AGA NB-13**

Transmission factor calculated for partially turbulent and fully turbulent flow considering roughness, bend index, and Reynolds number.

**Friction Factor - Panhandle A**

Panhandle equations do not consider pipe roughness; instead, an efficiency factor is used; less conservative than Colebrook or AGA.

**Friction Factor - Panhandle B**