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Line Sizing Calculation
Hydraulic analysis · Velocity & pressure drop · Two-phase flow · Baker chart flow regime · ASME B36.10M
ASME B36.10M Darcy-Weisbach Colebrook-White Baker (1954) Lockhart-Martinelli API RP 14E Ideal Gas Law
Gas / Vapour Properties
g/mol
MW ref: CH₄=16.04 · C₂H₆=30.07 · C₃H₈=44.10 · C₄H₁₀=58.12 · Air=28.97 · N₂=28.01 · CO₂=44.01 · H₂S=34.08 · H₂=2.02 · Steam=18.02 · Nat.Gas≈17–19
barg
°C
Ideal gas Z=1.0 · HC gas: 0.80–0.95
mPa·s
Calculated ρ_G = P·M / (Z·R·T)
kg/m³
Liquid Properties
kg/m³
mPa·s
Pipe Selection — ASME B36.10M
OD mm
WT mm
ID mm
Area mm²
mm
Carbon steel=0.046 · Stainless=0.015 · HDPE=0.007
Flow Conditions
m³/h
Mass Flow ṁ = ρ × Q
kg/h
Design Criteria & Pipe Length
m/s
Liquid: 1–3 m/s typical
bar/100m
m
m
Fittings & valves equiv.
m
Positive (+) = upward flow  ·  Negative (−) = downward  ·  0 = horizontal
📐 Formula Reference
ρ_G = P·M / (Z·R·T)   R=8.314 J/mol·K
V = Q / (π/4·ID²)  [m/s]
Re = ρ·V·D / μ  → Colebrook-White → f
ΔP/L = f·ρ·V² / (2D)  [Pa/m]
X_LM = √(ΔP_L/ΔP_G)  ·  φ²_G = 1 + C·X + X²   (gas mult.)
φ²_L = 1 + C/X + 1/X²   (liq. mult.)  ·  C: tt=20 vt=12 tv=10 vv=5
── API RP 14E (Two-Phase) ──
ρ_m = (12409·S_l·P + 2.7·R·S_g·P) / (198.7·P + R·T·Z)  [lb/ft³ × 16.02 → kg/m³]
  P=psia · T=Rankine · R=GOR (scf/stb) · S_l=liq SG · S_g=gas SG
V_e = c × 1.22 / √ρ_m  [m/s] · c per API RP 14E Table
  c=100 (corrosive·cont.) · c=125 (corrosive·int.)
  c=150–200 (non-corr./CRA·cont.) · c=250 (non-corr.·int.)
Enter input data on the left and click ▶ CALCULATE to see results.

Supports: Single Phase Liquid · Single Phase Gas/Vapour · Two-Phase Gas+Liquid
Single Phase
Total Pressure Drop
bar  (total pipeline incl. fittings)
Velocity
m/s
ΔP / 100m
bar/100m
Reynolds No.
Friction f
Mass Flow
kg/h
Flow Regime
Calculation Breakdown
ParameterValueUnit
Two Phase — Gas + Liquid
Flow Regime
Flow Pattern
Two-Phase ΔP / 100m
bar/100m
Gas ṁ_G
kg/h
Liquid ṁ_L
kg/h
j_G / j_L
m/s
Baker λ / ψ
Martinelli X_LM
Chisholm φ²_G
ΔP_G / 100m (gas only)
bar/100m
ΔP_L / 100m (liq only)
bar/100m
Gas Density ρ_G
kg/m³
Mix. Density ρ_m (API Eq.2)
kg/m³
Erosional V_e (c=)
m/s
ΔP_static (elevation)
bar
TOTAL ΔP (friction + static)
bar
Two-Phase Calculation Breakdown — Step by Step
Churchill (1977) friction  ·  Szilas (1975) Baker parameters  ·  Chisholm (1967) multiplier  ·  API RP 14E erosion
ParameterValueUnit
Baker Flow Regime Map & Illustrations — Baker (1954) · Horizontal Pipeline
Baker Chart — Operating Point (●) · B_x = G_L/(λ·ψ) vs B_y = G_G·λ  [kg/m²s]
All Flow Regime Illustrations — Highlighted = Current Operating Regime
Light blue = gas phase · Blue = liquid phase · Dark dots = liquid droplets · Flow: left → right