Pressure Drop Calculator

Single Phase Analysis for Liquids & Gases in Piping Systems

System Configuration

Fluid Properties

Pipe & Flow Parameters

Primary Results

Inlet Pressure: -
Outlet Pressure: -
Total Pressure Drop: -
Fluid Velocity: -

Enhanced Results

Pipe Geometry

Internal Diameter: -
Pipe Roughness: -
Flow Area: -
Effective Length: -

Flow Characteristics

Reynolds Number: -
Flow Regime: -
Friction Factor: -
Velocity Head: -

Pressure Analysis

Friction Drop: -
Elevation Drop: -
Ξ”P/Length: -
Head Loss: -

Flow Rate Summary

Volumetric Flow: -
Mass Flow: -
Residence Time: -
Method Used: -

Actions

Technical Notes

Variable Definitions

  • L: effective length (m) = straight length + equivalent length.
  • D: internal diameter (m) from DN & schedule database; Ξ΅: absolute roughness (m) from material.
  • Q: volumetric flow at operating conditions (mΒ³/s); ṁ: mass flow (kg/s).
  • ρ: fluid density (kg/mΒ³); ΞΌ: dynamic viscosity (PaΒ·s).
  • v: velocity (m/s) = Q/A; Re: Reynolds number = ρvD/ΞΌ (or mΜ‡D/(ΞΌA) for mass-flow gas form).
  • f: Darcy friction factor (–).
  • Ξ”z: elevation change inletβ†’outlet (m).
  • Ξ”P: pressure change (Pa or kPa; displayed as kPa/psi).

Formulas / Logic

  • Darcy–Weisbach: Ξ”P = fΒ·(L/D)Β·(ρvΒ²/2) + ρgΞ”z (single-phase, constant density).
  • Friction factor: laminar f=64/Re; turbulent uses Haaland explicit Colebrook approximation: 1/√f = βˆ’1.8 log10[(Ξ΅/3.7D)^1.11 + 6.9/Re].
  • Hazen–Williams (water): headloss screening for turbulent water using a default Cβ‰ˆ120 (verify for pipe condition).
  • Gas density from MW & Z: ρ = (PΒ·MW)/(ZΒ·RΒ·T) with P absolute and R universal gas constant.
  • Isothermal gas (rigorous): integrates isothermal Darcy form with variable density (constant f assumption) and iterates elevation using average density.
  • Weymouth / Panhandle: empirical pipeline gas equations on standard flow basis; tool converts mass flow β†’ standard flow internally.
Use Darcy–Weisbach for most engineering applications. Pipeline gas equations are for long-distance transmission and have strict applicability.

Assumptions / Notes

  • Minor losses are represented via equivalent length only (no explicit K table). Include valves/fittings as equivalent length or via project standards.
  • Constant-density Darcy is acceptable for liquids and for gas only when Ξ”P < ~10% of absolute pressure (screening rule).
  • Compressible gas model assumes isothermal flow, constant Z, and constant friction factor (screening); for high accuracy, iterate properties along the line.
  • Elevation term uses inlet/average density; for gases with large elevation and Ξ”P, verify with a dedicated tool.
  • Velocity warnings are generic; confirm against company/API erosional velocity practices as applicable.

Standards / References

  • Crane TP-410: Flow of Fluids (Darcy–Weisbach, minor losses, friction factor practice).
  • ISO 5167 concepts for flow measurement are not used directly here (no restriction devices modeled).
  • Gas pipeline correlations: Weymouth and Panhandle A/B (industry practice for transmission; use with stated ranges).
  • Moody/Colebrook friction factor basis; Haaland explicit approximation used for robustness.
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