# Natural Gas - Pipe Sizing

## Sizing low pressure natural gas pipe lines - imperial units

The tables below can be used for natural gas pipe sizing.

### Steel Pipe - Schedule 40

Capacity of Pipe (MBH ≈ CFH) | |||||||
---|---|---|---|---|---|---|---|

Pipe Size (in) | Pipe Length (ft) | ||||||

Nominal | Inside diameter | 10 | 20 | 40 | 80 | 150 | 300 |

1/2 | 0.622 | 120 | 85 | 60 | 42 | 31 | 22 |

3/4 | 0.824 | 272 | 192 | 136 | 96 | 70 | 50 |

1 | 1.049 | 547 | 387 | 273 | 193 | 141 | 100 |

1 1/4 | 1.380 | 1200 | 849 | 600 | 424 | 310 | 219 |

1 1/2 | 1.610 | 1860 | 1316 | 930 | 658 | 480 | 340 |

2 | 2.067 | 3759 | 2658 | 1880 | 1330 | 971 | 686 |

2 1/2 | 2.469 | 6169 | 4362 | 3084 | 2189 | 1593 | 1126 |

3 | 3.068 | 11225 | 7938 | 5613 | 3969 | 2898 | 2049 |

4 | 4.026 | 23479 | 16602 | 11740 | 8301 | 6062 | 4287 |

5 | 5.047 | 42945 | 30367 | 21473 | 15183 | 11088 | 7841 |

6 | 6.065 | 69671 | 49265 | 34836 | 24632 | 17989 | 12720 |

8 | 7.981 | 141832 | 100290 | 70916 | 50145 | 36621 | 25895 |

- pressure less than
*1 1/2 psig* - common to use fittings factor
*1.5*- equivalent pipe length in table above = pipe length +*50%* - pressure drop
*0.5 inches water column* - specific gravity of natural gas
*0.6* - energy content in natural gas
*1000 Btu/ft*^{3 }(37.26 MJ/m^{3}) - steel pipes schedule 40

For natural gas the nominal *BTU/ft ^{3 } *varies from about

*900 to 1100 BTU/ft*. In general it is common to set

^{3}*1 Cubic Foot (ft*^{3}, CF) = Approx 1000 BTUs*1 CFH = 1 MBH (MBH is thousands of BTUs per hour)*

### Related Mobile Apps from The Engineering ToolBox

- free apps for offline use on mobile devices.

### Copper Tubing - type K

Capacity of Pipe (MBH ≈ CFH) | ||||||
---|---|---|---|---|---|---|

Pipe Size (in) | Pipe Length (ft) | |||||

Nominal | Outside Diameter | Inside Diameter | 10 | 20 | 40 | 80 |

1/4 | 3/8 | 0.305 | 15 | 10 | 7 | 5 |

3/8 | 1/2 | 0.402 | 33 | 24 | 17 | 12 |

1/2 | 5/8 | 0.527 | 74 | 52 | 37 | 26 |

5/8 | 3/4 | 0.652 | 138 | 97 | 69 | 49 |

3/4 | 7/8 | 0.745 | 203 | 143 | 101 | 72 |

1 | 1 1/8 | 0.995 | 469 | 332 | 235 | 166 |

1 1/4 | 1 3/8 | 1.245 | 894 | 632 | 447 | 316 |

- pressure less than
*1 1/2 psig* - common to use fittings factor
*1.5*- equivalent pipe length in table above = pipe length +*50%* - pressure drop
*0.5 inches water column* - specific gravity of natural gas
*0.6* - energy content in natural gas
*1000 Btu/ft*^{3 }(37.26 MJ/m^{3}) - One MBH is equivalent to
*1000 BTU's per hour* - copper tubing type K

### Copper Tubing - type L

Capacity of Pipe (MBH ≈ CFH) | ||||||
---|---|---|---|---|---|---|

Pipe Size (in) | Pipe Length (ft) | |||||

Nominal | Outside Diameter | Inside Diameter | 10 | 20 | 40 | 80 |

1/4 | 3/8 | 0.315 | 16 | 11 | 8 | 6 |

3/8 | 1/2 | 0.430 | 41 | 29 | 20 | 14 |

1/2 | 5/8 | 0.545 | 81 | 58 | 41 | 29 |

5/8 | 3/4 | 0.666 | 146 | 103 | 73 | 52 |

3/4 | 7/8 | 0.785 | 236 | 167 | 118 | 84 |

1 | 1 1/8 | 1.025 | 511 | 362 | 256 | 181 |

1 1/4 | 1 3/8 | 1.265 | 936 | 662 | 468 | 331 |

- pressure less than
*1 1/2 psig* - common to use fittings factor
*1.5*- equivalent pipe length in table above = pipe length +*50%* - pressure drop
*0.5 inches water column* - specific gravity of natural gas
*0.6* - energy content in natural gas
*1000 Btu/ft*^{3 }(37.26 MJ/m^{3}) - One MBH is equivalent to
*1000 BTU's per hour* - copper tubing type L

*1 Btu/h = 0.293 W**1 lb = 0.4536 kg**1 ft (foot) = 0.3048 m**1 in water = 248.8 N/m*^{2}(Pa) = 0.0361 lb/in^{2}(psi) = 25.4 kg/m^{2}= 0.0739 in mercury*1 psi (lb/in*^{2}) = 6,894.8 Pa (N/m^{2})