FM – Fundamental Equation

FM – Fundamental Equation

This basic equation is referred to the Fundamental Flow Equation, also known as the General Flow equation.
Starting with Bernoulli’s equation, researchers have developed a formula for calculating the pressure drop in a gas pipeline, considering the pipe diameter, length, elevations along the pipe, gas flow rate and the gravity and compressibility of the gas as shown in this manual.

  • 𝑄 βˆ’ Flow Rate (ft3/day)
  • 𝐷 βˆ’ Internal Pipe Diameter (in)
  • 𝐿 βˆ’ Length of Pipeline(mi)
  • 𝑃1 βˆ’ Upstream Pressure (psi)
  • 𝑃2 βˆ’ Downstream Pressure (psi)
  • 𝐺 βˆ’ Gas Specific Gravity
  • 𝑃𝑏 βˆ’ Pressure Base (psi)
  • 𝑇𝑏 βˆ’Temperature Base (Β°R)
  • 𝑇𝑓 βˆ’ Gas Flowing Temperature (Β°R)
  • 𝑍 βˆ’ Compressibility Factor
PTLB Hydraulics 2.6 Intro 2.png
  • 𝐹 βˆ’ Transmission Factor
  • 𝑓 βˆ’ Friction Factor
  • π‘˜ βˆ’ Pipe Roughness
  • 𝐷 βˆ’ Internal Diameter (in)

Input Parameters

  1. To create a new case, click the β€œAdd Case” button
  2. Select the Unknown and desired Flow Equation.
  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.
  • Temperature base(Β°F)
  • Pressure base(psia)
  • Gas Flowing Temperature(Β°F)
  • Gas Specific Gravity
  • Compressibility Factor
  • Pipeline Efficiency Factor
  • Upstream Pressure(psig)
  • Flow Rate(MCFD)
  • Internal Pipe Diameter(in)
  • Length of Pipeline(mi)
  • Upstream Elevation(ft)
  • Downstream Elevation(ft)

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.
  • Flow Rate(ft/sec.)
  • Transmission Factor
  • Velocity(ft/sec.)
  • Upstream Pressure(psi)
  • Transmission Factor
  • Velocity(ft/sec.)
  • Downstream Pressure(psi)
  • Transmission Factor
  • Velocity(ft/sec.)
  • Internal Pipe Diameter(in)
  • Transmission Factor
  • Velocity(ft/sec.)
  • Erosional Velocity
  • Sonic Velocity

Flow Rate

PTLB Hydraulics-FM Output Revision_Flowrate.png

Upstream Pressure

PTLB Hydraulics-FM Output Revision_Upstream.png

Downstream Pressure

PTLB Hydraulics-FM Output Revision_Downstream.png

Internal Pipe Diameter

PTLB Hydraulics-FM Output Revision_IPD.png

Related Links

Pipeline Hydraulics

Pipeline HUB User Resources

Table of Contents
Table of Pages
  1. Pipeline HUB User Resources
  2. AC Mitigation PowerTool
  3. API Inspectors Toolbox
  4. Horizontal Directional Drilling PowerTool
  5. Crossings Workflow
  6. Pipeline Toolbox
  7. Encroachment Manager
  8. PRCI AC Mitigation Toolbox
  9. PRCI Thermal Analysis for Hot-Tap Welding
  10. PRCI River-X
  11. PRCI RSTRENG
  12. RSTRENG+
  13. Ad-hoc Analysis
  14. Database Import
  15. Data Availability Dashboard
  16. ESRI Map
  17. Report Builder
  18. Hydrotest PowerTool
  19. Investigative Dig PowerTool
  20. Hydraulics PowerTool
  21. External Corrosion Direct Assessment Procedure - RSTRENG
  22. Canvas
  23. Definitions
  24. Pipe Schedule and Specifications Tables