Calculators›Pig Speed
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Pigging Operations Toolkit

Speed · Flow Rate · Location Tracking

Pipeline Pig Speed Calculator
Calculate pig velocity, required flow rate, and track pig location in gas pipelines per API RP 1171 and ASME B31.8. Optimizes pigging operations for cleaning, inspection (ILI), and batching with pig type-specific speed limits.
Calculation Mode:

Calculate Speed from Flow

MMSCFD

Pipeline Specifications

miles
in

Operating Conditions

psig
°F
%

📚 Learn the Theory

Detailed coverage of pigging operations, pig velocity calculations, surge pressures, and launcher/receiver design per API RP 1171.

Read Engineering Guide →

Formula (Pig Speed)

Vpig = Vgas × fpig × (1 - β)
Vgas = Qactual / A (ft/s)
Qactual = Qstd × (Pstd/P) × (T/Tstd) × Z
fpig = Pig efficiency factor (0.85-0.95)
β = Bypass fraction (0.02-0.10 typical)

Standards & References

  • API RP 1171
    Functional Integrity of Natural Gas Pipelines
  • API RP 1160
    Managing System Integrity for Hazardous Liquid Pipelines
  • ASME B31.8
    Gas Transmission and Distribution Piping
  • NACE SP0102
    In-Line Inspection of Pipelines

Engineering Notes

  • ILI Tools: MFL and UT tools require 2-6 ft/s for data quality per API RP 1171.
  • Speed Limits: Maximum 15 ft/s for most pigs; excessive speed causes wear and potential damage.
  • Minimum Speed: At least 2 ft/s to prevent stalling in uphill sections.
  • Bypass Effect: Higher bypass reduces pig speed relative to gas velocity.
  • Gas Density: Speed varies with pressure and temperature due to gas compressibility.

Pig Type Speed Ranges

  • Foam Pigs: 3-8 ft/s optimal (max 15 ft/s)
  • Cleaning Pigs: 3-10 ft/s optimal (max 12-15 ft/s)
  • MFL/UT ILI: 2-5 ft/s optimal (max 6 ft/s for data quality)
  • Gauge Pigs: 3-8 ft/s optimal (max 10 ft/s)

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