Gas Pipe Sizing Calculator

Flow Conditions

Flow Rate

MMscfd

Operating Pressure

psig

Operating Temperature

°F

Design Parameters

Service Type

Specific Gravity

Base Pressure

psia

Base Temperature

°F

Design Requirements

Required MAOP

psig

Design Standard

Location Class (B31.8)

Manufacturing Details

Seam Type

Apply Manufacturing Tolerance (12.5%) Note: For B31.8, tolerance is already included in design factor. This setting only applies to B31.3 calculations.

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Gas Pipe Sizing Results

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Use Erosional Limit or Max: ft/s

💡 Velocity Filtering: Check "Use Erosional Limit" to filter by API RP 14E erosional velocity (V_e = C/√ρ), or uncheck to set a custom maximum velocity limit. Uncheck "Show All" to hide pipes exceeding the limit.

Pipe Size	Material	Velocity (ft/s)	Erosion Status	MAOP (psig)	MAOP Status	Safety Margin

📋 Calculation Methodology

Comprehensive Analysis

Evaluates all pipe size and material combinations simultaneously, analyzing both velocity constraints per API RP 14E and pressure requirements per ASME B31.3/B31.8.

Results show viable options ranked by safety margin, velocity status, and overall suitability for your application.

🔬 Key Formulas

Erosional Velocity (API RP 14E)

Ve = C / √ρ

C = Service constant (60-125)
ρ = Gas density (lb/ft³)

MAOP (B31.8)

P = (2St/D) × F × E × T

S = SMYS | F = Location factor | E = Joint factor | T = Temp factor

MAOP (B31.3)

P = (2SE × t × Y) / D

S = Allowable stress | E = Joint factor | Y = Wall thickness coefficient

⚠️ Important Notes

Uses real gas calculations with Papay compressibility correlation
Erosion Status Criteria:
- Safe: V < 50% erosional limit AND < 50% critical velocity
- Caution: V between 50-80% of erosional limit
- Erosional Risk: V > 80% of erosional limit (API RP 14E)
- Critical Flow Risk: V > 50% of sonic velocity
Manufacturing Tolerance: For B31.8, tolerance is already included in design factors (F). For B31.3, 12.5% tolerance is applied per code requirements
D/t ratio limited to 96 per ASME B31.8
Results are for preliminary design - verify with licensed engineer

Standards & References

API RP 14E
Erosional Velocity Guidelines
ASME B31.3
Process Piping
ASME B31.8
Gas Transmission Systems
CFR 49 Part 192
Pipeline Safety Standards

Flow Conditions

Design Parameters

Design Requirements

Manufacturing Details

📚 Learn the Theory

Gas Pipe Sizing Results

📋 Calculation Methodology

🔬 Key Formulas

⚠️ Important Notes

Analysis Summary

Standards & References

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