API 14E Phase Flow Calcs



API 14 E two Phase Flow pressure drop calculations and two phase baker pressure drop calculations

Calculation Reference
Piping Calculations
Pressure Drop in Pipes
Processing Plant

API 14E is a guideline provided by the American Petroleum Institute (API) for designing offshore production facilities. It includes an empirical method for calculating two-phase flow pressure drop in pipes. The Baker method is another widely used approach for predicting pressure drops in two-phase flow systems. Both methods are described below:

  1. API 14E Two-Phase Flow Pressure Drop Calculation:

The API 14E method estimates pressure drop in horizontal pipes with two-phase flow (gas and liquid) using the following equation:

ΔP = K * L * (ρ_L * ρ_G) / (ρ_L + ρ_G)


  • ΔP = pressure drop (psi)
  • K = an empirical factor (psi/ft)
  • L = pipe length (ft)
  • ρ_L = liquid density (lb/ft³)
  • ρ_G = gas density (lb/ft³)

The empirical factor (K) depends on the flow regime and can be determined from charts or tables provided in the API 14E guidelines. It's important to note that the API 14E method is specific to the oil and gas industry and may not be applicable to other industries or fluids.

  1. Baker Two-Phase Flow Pressure Drop Calculation:

The Baker method is a more general approach for calculating pressure drop in two-phase flow systems. It involves determining the flow pattern (e.g., stratified, annular, or slug flow) and then using the appropriate correlations for each flow pattern to calculate pressure drop. The method usually involves the following steps:

a) Calculate the dimensionless parameters, such as Lockhart-Martinelli parameter (X) and Froude number (Fr), to determine the flow pattern.

b) Determine the flow pattern based on dimensionless parameters and flow maps.

c) Use the appropriate pressure drop correlations for the identified flow pattern. These correlations are usually based on experimental data and can involve frictional, gravitational, and accelerational pressure drops.

d) Sum the individual pressure drop components to obtain the total pressure drop in the pipe.

Both the API 14E and Baker methods can be used to estimate pressure drops in two-phase flow systems. However, it's essential to choose the appropriate method based on the specific industry, fluid properties, and flow conditions. Additionally, always consult the relevant guidelines and literature for accurate correlations and data.

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29 Jun 2015
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Comments: 1
JohnDoyle[Admin] 7 years ago
Sorry this has taken so much time to publish I found a few stray calculations waiting in my approvals folder. Thanks for your good work I have awarded a free 3 month XLC Pro subscription by way of thanks.