# C250 – API MPMS 2004: Calculation of Cpl

## Description

This calculates the correction factor due to pressure.

## References

API MPMS Chapter 11.1 – Temperature and Pressure Volume Correction Factors for Generalized Crude Oils, Refined Products, and Lubricating Oils (ASTM D 1250-04; IP 200/04) (First edition 2004, Addendum 1 2007)

Kelton calculation reference C250

This calculation is used by:

F060/K214 – API Density Referral 2004

## Options

### Thermal Expansion Coefficient

- User Entered

Select this option if you know the thermal expansion factor at 60°F of the hydrocarbon you are performing calculations on. You will not need to select a commodity group if you select this option.

- Calculated

Select this option if you do not know the thermal expansion factor at 60°F of the hydrocarbon you are performing calculations on.

### Commodity Group

- Crude Oil

- Fuel Oils

- Jet Fuels

- Transition Zone

- Gasoline

- Lubricating Oil

Select appropriate commodity so that the correct K values are used in the calculation. They are needed to calculate the thermal expansion factor of the liquid.

## Constants

Constants as defined by API

Commodity group | K_{0} |
K_{1} |
K_{2} |

Crude oil | 341.0957 | 0 | 0 |

Fuel oils | 103.8720 | 0.2701 | 0 |

Jet fuels | 330.301 | 0 | 0 |

Transition Zone | 1489.067 | 0 | -0.0018684 |

Gasolines | 192.4571 | 0.2438 | 0 |

Lubricating oil | 0 | 0.34878 | 0 |

## Calculation

### Scaled compressibility factor

The scaled compressibility factor, F_{p} (in psi^{-1}), is calculated by:

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

T_{f68} |
= | Temperature shifted to ITPS-68 basis |

ρ_{f68} |
= | Base density shifted to ITPS-68 basis |

### Pressure correction factor

The pressure correction factor, C_{pl}, is calculated by:

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

F_{p} |
= | Scaled compressibility Factor |

P | = | Pressure |

P_{e} |
= | Vapour pressure |