API 2540 - Volume Correction Factor

This procedure calculates the Volume Correction Factor (VCF) for correcting from the density at base conditions (60°F and 0 psig) to alternate temperature and pressure conditions.

Step 1:
Unless otherwise directed, check the input values to determine if they are in the range of this standard. The following are the valid limits.

The following table give ,𝜌-60.limits for the various commodity groups.



If P<0 psig then P=0 and continue with procedure.

Step 2:
Shift the input ,𝜌-60. value to the density basis ,𝜌-∗.. If the commodity group has been specified, then compute using the following formulas.

Where:

𝐾₀ − Coefficient in correlation for 𝛼60(kg²/m⁶℉)

𝐾₁ − Coefficient in correlation for 𝛼60(kg/m³℉)

𝜌₆₀ − Density at base conditions (60℉ and 0psig)(kg/m³)

  Step 3:
In preparation of calculating the correction factor due to temperature, ,𝐶-𝑇𝐿., determine the coefficient of thermal expansion at the base temperature of 60°F, ,𝛼-60.. The coefficients used in this equation depend upon the commodity group. Use the same coefficients that were used in Step 3.

Where:

𝐾₀ − Coefficient in correlation for 𝛼60(kg²/m⁶℉)

𝐾₁ − Coefficient in correlation for 𝛼60(kg/m³℉)

𝜌^∗ − Density at shifted base conditions(kg/m³)

Step 4:
Calculate the difference in the Reference Temperature and the Liquid Temperature. ∆𝑡 = 𝑡 − 𝑇₁

∆𝑡 − Reference Temperature minus the Liquid Temperature(℉)

Use this value to calculate the volume correction factor due to temperature, 𝐶_𝑇𝐿:

𝐶_𝑇𝐿 = 𝑒𝑥𝑝{−𝛼₆₀∆𝑡[1 + 0.8𝛼₆₀(∆𝑡)]}

Step 5:
Correct a volume measured at alternate conditions to base conditions and/or correct base density to alternate conditions.

𝜌 = 𝐶_𝑇𝐿 • 𝜌₆₀

𝑉₆₀ = 𝑉_𝑡 • 𝐶_𝑇𝐿

Where

𝜌 − Density at alternate conditions(kg/m³)

𝐶_𝑇𝐿 − Volume Correction Factor due to Temperature

𝑉₆₀ − Volume at base conditions (60℉ and 0psig)

𝑉_𝑡 − Volume at alternate temperature

𝜌₆₀ − Density at base conditions (60℉ and 0psig) (kg/m³)

 

Input Parameters

1. To create a new case, click the “Add Case” button
2. Select the API 2540 – Volume Correction Factor application from the Miscellaneous module list.
3. Enter Case Name, Location, Date and any necessary notes.
4. Fill out all required fields.
5. Make sure the values you are inputting are in the correct units.
6. Click the CALCULATE button.

• Liquid Type
• Specific Gravity Range
• Ko – API Correlation Parameter
• K1 – API Correlation Parameter
• Reference Temperature (°F)
• Specific Gravity
• Liquid Temperature (°F)

 

Outputs/Reports

1. View the results.
2. If an input parameter needs to be edited be sure to hit the CALCULATE button after the change.
3. To SAVE, fill out all required case details then click the SAVE button.
4. To rename an existing file, click the SAVE As button. Provide all case info then click SAVE.
5. To generate a REPORT, click the REPORT button.
6. The user may export the Case/Report by clicking the Export to Excel/PowerPoint icon.
7. To delete a case, click the DELETE icon near the top of the widget.

• Coefficient of Thermal Expansion
• Volume Correction Factor for Thermal Expansion
• Corrected Specific Gravity

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