An option is provided to select the primary flowrate calculation method. Typically the McCrometer V-Cone calculation uses gross volume as the primary flowrate.

Symbol | Description | Units |
---|---|---|

q_{g} |
Gross volume flowrate | m^{3}/s |

ρ_{1} |
Upstream density | kg/m^{3} |

Δp | Differential pressure | Pa |

D_{0} |
Internal diameter of the pipe at calibration | m |

β_{0} |
Uncorrected beta ratio | - |

C_{d} |
Coefficient of discharge | - |

Y | Adiabatic expansion factor | - |

F_{a} |
Thermal expansion factor | - |

Symbol | Description | Units |
---|---|---|

q_{m} |
Mass flowrate | kg/s |

ρ_{1} |
Upstream density | kg/m^{3} |

Δp | Differential pressure | Pa |

D_{0} |
Internal diameter of the pipe at calibration | m |

β_{0} |
Uncorrected beta ratio | - |

C_{d} |
Coefficient of discharge | - |

Y | Adiabatic expansion factor | - |

F_{a} |
Thermal expansion factor | - |

Symbol | Description | Units |
---|---|---|

d | Orifice diameter at upstream temperature | m |

d_{0} |
Orifice diameter at calibration temperature | m |

λ_{d} |
Expansion coefficient of the orifice plate material | /°C |

t_{0} |
Pipe/Cone calibration temperature | °C |

t_{1} |
Upstream temperature | °C |

Symbol | Description | Units |
---|---|---|

D | Pipe diameter at upstream temperature | m |

D_{0} |
Pipe diameter at calibration temperature | m |

λ_{D} |
Expansion coefficient of the pipe material | /°C |

t_{0} |
Pipe/Cone calibration temperature | °C |

t_{1} |
Upstream temperature | °C |

Symbol | Description | Units |
---|---|---|

β_{0} |
Beta ratio | - |

d_{0} |
Orifice diameter at calibration temperature | m |

D_{0} |
Pipe diameter at the calibration temperature | m |

Symbol | Description | Units |
---|---|---|

β | Beta ratio | - |

d | Orifice diameter at the upstream temperature | m |

D | Pipe diameter at the upstream temperature | m |

An operator selection is provided for the coefficient of discharge. The coefficient of discharge is either derived from an operator entry or from a look-up table. If the look-up table is selected, the coefficient of discharge is obtained from the Reynolds' number to discharge coefficient look-up table (10 entries for the coefficient of discharge and Reynolds' number, with interpolation between points).

Symbol | Description | Units |
---|---|---|

C_{d} |
Interpolated coefficient of discharge | - |

R | Calculated reynold's number | - |

R_{l} |
Curve reynolds number ≤ calculated reynolds number | - |

R_{u} |
Curve reynolds number ≥ calculated reynolds number | - |

C_{l} |
Curve coefficient of discharge corresponding to R_{l} |
- |

C_{u} |
Curve coefficient of discharge corresponding to R_{u} |
- |

In the case of liquids this figure will always be 1.

For option: V-Cone Model - Standard

For option: V-Cone Model - Wafer

Symbol | Description | Units |
---|---|---|

Y | Adiabatic expansion factor | - |

β_{0} |
Uncorrected beta ratio | - |

k | Isentropic exponent | - |

R | Simplification term | - |

Δp | Differential pressure | bar a |

p_{1} |
Upstream pressure | bar a |

Symbol | Description | Units |
---|---|---|

F_{a} |
Thermal expansion factor | - |

β | Corrected beta ratio | - |

D | Internal pipe diameter at working conditions | m |

β_{0} |
Uncorrected beta ratio | - |

D_{0} |
Internal pipe diameter at calibration temperature | m |

Symbol | Description | Units |
---|---|---|

Re_{D} |
Reynolds number | - |

q_{m} |
Mass flowrate | kg/s |

µ_{1} |
Dynamic viscosity | Pa.s |

D | Internal pipe diameter at the upstream temperature | m |

Symbol | Description | Units |
---|---|---|

Δω | Permanent pressure loss | bar a |

β | Corrected beta ratio | - |

Δp | Differential pressure | bar a |

Symbol | Description | Units |
---|---|---|

p_{3} |
Fully recovered pressure | bar a |

p_{1} |
Upstream pressure | bar a |

Δω | Permanent pressure loss | bar a |

An option is provided to select the upstream temperature calculation method.

Symbol | Description | Units |
---|---|---|

t_{1} |
Upstream temperature | °C |

t_{3} |
Temperature at the fully recovered pressure position | °C |

p_{1} |
Upstream pressure | bar a |

p_{3} |
Fully recovered downstream pressure | bar a |

Y | Specific Heat Ratio | - |

For option: Temperature Transmitter Location - Downstream

-Downstream Pressure is used in the place of Recovery Pressure.

Symbol | Description | Units |
---|---|---|

t_{1} |
Upstream temperature | °C |

t_{3} |
Temperature at the fully recovered pressure position | °C |

Δt | Difference in temperature | °C |

Δω | Permanent pressure loss | bar a |

p_{1} |
Upstream pressure | bar a |

For option: Temperature Transmitter Location - Downstream

-Differential Pressure, in bar a, is used in the place of Permanent Pressure Loss.

For option: Temperature Transmitter Location - Upstream

-The user inputted value for upstream temperature is used and upstream temperature is no longer an output. The section of the above which calculates the upstream temperature is ommited.

For option: Temperature Exponent Method - User Entered

-The user inputted value for temperature exponent is used in the Upstream temperature(Isentropic Exponent Method) calculation in the place of the calculated value for Temperature Exponent from the Isentropic Exponent using the equation: 1-Y/Y.

For option: Discharge Coefficient - Fixed

-The user inputted value for the dicharge coefficient is used and dicharge coefficient is no longer an output. The section of the above which calculates the discharge coefficient is ommited.

- McCrometer - Flow calculations for the V-Cone Flowmeters, Literature part #24509-54 Revision 2.5, 2000
- McCrometer - Flow calculations for the V-Cone and Wafer-Cone Flowmeters, Literature part #24509-54 Revision 3.2, 2008