# C256 – Gas Density Computation PTZ

## Description

This calculates either the line or standard density depending on the option selected.

## References

Kelton calculation reference C256

FLOCALC calculation reference F065

KIMS calculation reference K205

## Options

### Solve for

- Line density

- Standard density

Select option based on which density you wish to calculate.

### Calculate

- Relative density

Allows user to calculate the output density as a relative density.

### Calculate from

- Standard density

- Relative density

- Molecular weight

- Line density

Select option based on the data you wish to enter.

## Constants

Molar gas constant – R = 8.314621 Jmol^{-1}K^{-1}

## Calculation

The calculation uses the following pressure, temperature and compressibility relationships to calculate line or standard density.

Where | ||
---|---|---|

M | = | Molelcular weight |

P | = | Pressure |

P_{b} |
= | Pressure at base conditions |

T | = | Temperature |

T_{b} |
= | Temperature at base conditions |

Z | = | Compressibility factor |

Z_{b} |
= | Compressibility factor at base conditions |