Liquid Line Sizing Calculator

Flow Conditions

Flow Rate

Specific Gravity

Water = 1.0, typical range: 0.7-1.6

Viscosity

Water @ 60°F ≈ 1.0 cP

Pipe Properties

Pipe Standard

Pipe Material

Roughness

Commercial steel (new): 0.00015 ft per Crane TP-410

Design Criteria

Max Velocity

ft/s

Typical: 5-15 ft/s

Max Pressure Drop

psi/100ft

Economic optimum: 1-2 psi/100ft

Service Type

📚 Learn the Theory

Understand liquid line sizing principles, calculations, and industry applications

Read Engineering Guide →

🔬 Key Formulas

Reynolds Number

Re = 3160 × Q × SG / (d × μ)

Q = Flow rate (GPM)
SG = Specific gravity
d = Inside diameter (inches)
μ = Viscosity (cP)
Ref: Crane TP-410

Friction Factor (Swamee-Jain - CORRECTED)

f = 0.25 / [log₁₀(ε/(3.7D) + 5.74/Re⁰·⁹)]²

ε = Absolute roughness (ft)
Valid for: Turbulent flow, Re > 4000

Pressure Drop (Darcy-Weisbach)

ΔP = 1.348 × f × SG × Q² / D⁵

Result in psi per 100 feet

⚠️ Important Notes

Formula Corrections: Reynolds constant (3160 per Crane TP-410) and Swamee-Jain equation corrected
Laminar flow (Re < 2100): f = 64/Re
Turbulent flow (Re > 4000): Swamee-Jain explicit equation
Typical velocity ranges: Suction 1-5 ft/s, Discharge 5-15 ft/s
Results are for preliminary design - verify with licensed engineer

💡 Quick Guide

✅ Works For:

• Water, crude oil, diesel, gasoline, fuel oil
• Any Newtonian liquid (single-phase)
• Viscosity range: 0.5 - 10,000 cP

❌ NOT For:

• Gas-liquid mixtures, steam, flashing liquids
• Slurries, polymers, non-Newtonian fluids
• Compressible flow

🎯 Velocity Guidelines:

• Pump suction: 1-5 ft/s
• Water discharge: 5-15 ft/s
• Oil pipelines: 3-8 ft/s
• Heavy oils: 2-5 ft/s

⚡ Key Tips:

• Use viscosity at actual operating temperature
• Target Re > 4000 for turbulent flow (more efficient)
• Cold oil = higher viscosity = higher ΔP
• Heating heavy oils reduces pumping costs
• Aged pipe: increase roughness to 0.003-0.005 ft

💧 Common Fluids @ 60°F

Fluid	SG	μ (cP)
Water	1.00	1.1
Gasoline	0.72	0.6
Diesel	0.85	4.0
Kerosene	0.81	2.2
Light Crude	0.86	10-20
Med Crude	0.92	50-100
Heavy Crude	0.95	200-1000
Fuel Oil #2	0.87	5
Fuel Oil #6	0.98	900*
Ethanol	0.79	1.2
Glycol (50%)	1.07	5.5

*Requires heating. μ varies greatly with temp.

Pipe Roughness Values

Material	ε (ft)
Carbon Steel (new)	0.00015
Carbon Steel (corroded)	0.003-0.01
Stainless Steel	0.000005
PVC	0.000005
Copper	0.000005

⚠️ Limitations

Newtonian liquids only
Single-phase flow
No gas-liquid mixtures
No slurries/polymers
Viscosity < 10,000 cP

🎯 Velocity Guide

Pump Suction	1-5 ft/s
Water Discharge	5-15 ft/s
Oil Pipelines	3-8 ft/s
Heavy Oils	2-5 ft/s

Target Re > 4000 for turbulent flow (more efficient)

Frequently Asked Questions

What method does this liquid line sizing calculator use?

This calculator uses the Darcy-Weisbach equation with Swamee-Jain friction factor to analyze pressure drop, velocity, Reynolds number, and flow regime for all standard pipe sizes. It evaluates multiple pipe diameters simultaneously.

What are typical velocity limits for liquid pipeline sizing?

Typical liquid pipeline velocities range from 3–15 ft/s for general service. Pump suction lines require lower velocities to maintain adequate NPSH. The economic optimum pressure drop is typically 1–2 psi per 100 ft of pipe.

How does the calculator recommend a pipe size?

The calculator recommends pipe sizes that meet velocity criteria (3–15 ft/s), maintain turbulent flow (Re > 4,000), and keep pressure drop within the specified maximum limit. It flags pipes with excessive velocity or low Reynolds number.

Flow Conditions

Pipe Properties

Design Criteria

📚 Learn the Theory

Liquid Line Sizing Results

🔬 Key Formulas

⚠️ Important Notes

💡 Quick Guide

Analysis Summary

💧 Common Fluids @ 60°F

Pipe Roughness Values

⚠️ Limitations

🎯 Velocity Guide

Frequently Asked Questions

📊 Related Calculators

Liquid Line Sizing Calculator

Flow Conditions

Pipe Properties

Design Criteria

📚 Learn the Theory

Liquid Line Sizing Results

🔬 Key Formulas

⚠️ Important Notes

💡 Quick Guide

Analysis Summary

💧 Common Fluids @ 60°F

Pipe Roughness Values

⚠️ Limitations

🎯 Velocity Guide

Frequently Asked Questions

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