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CNG Gas Transport Calculator

Tube Trailer Volume ยท Virtual Pipeline Logistics ยท Cascade Systems

CNG Gas Transport Calculator
Calculates deliverable gas volumes for compressed natural gas (CNG) tube trailers and cascade storage systems. Uses real gas law with pressure-dependent Z-factor (Hall-Yarborough correlation) for accurate volume calculations per NFPA 52 and DOT 49 CFR Part 178 standards.
Calculation Mode:

Tube Trailer Parameters

gal
Total cylinder water volume (typical: 6,000-12,000 gal)
psig
CNG standard: 3000-3600 psig
psig
Minimum usable pressure at destination

Gas Properties

ยฐF
Standard: 60ยฐF. Z-factor varies with T.
Engineering Notes:
  • Z-factor calculated using Hall-Yarborough correlation (1973)
  • Pipeline quality gas assumed: SG = 0.60, 1020 BTU/SCF
  • Cascade efficiency of 85% accounts for equalization losses per NFPA 52
  • 1 GGE (gasoline gallon equivalent) = 126.67 SCF natural gas

Frequently Asked Questions

How do you calculate CNG tube trailer capacity?

CNG tube trailer capacity is calculated from the number of tubes, tube dimensions, storage pressure, and gas compressibility factor. This calculator determines total gas volume at standard conditions per NFPA 52 and DOT transport regulations.

What regulations apply to CNG tube trailers?

CNG transport tubes must comply with DOT 49 CFR for pressure vessel transport, NFPA 52 for vehicular gaseous fuel systems, and ASME standards for high-pressure vessel design. Maximum transport pressure is typically 3,600 psig.

How does temperature affect CNG tube trailer volume?

Gas stored at higher temperatures has lower density, reducing the mass of gas per tube. The calculator applies real-gas compressibility corrections to account for temperature and pressure effects on stored CNG volume.

What is the typical storage pressure for CNG trailers?

CNG tube trailers typically operate at storage pressures of 2,400 to 3,600 psig. Higher pressures increase volumetric capacity but require heavier tube walls per DOT specifications.