Average Pressure Calculator
Computes average pipeline pressure using arithmetic, logarithmic, and integral averaging methods. Essential for accurate flow calculations in compressible gas systems per GPSA methodology.
Atmospheric Pressure (AGA):
Patm = 14.696 Ć (1 - 6.8753Ć10ā»ā¶ Ć h)5.2561
where h = elevation in feet
Standards & References
GPSA Engineering Data Book 14th Edition
ASME B31.8 Gas Transmission Piping Systems
U.S. Standard Atmosphere 1976 Model
API 14.3 Orifice Metering of Natural Gas
Important Notes
Arithmetic Average: Simple linear average suitable for liquid flow or low pressure drop gas flow (<10% change)
Hydraulic Average: Accounts for non-linear pressure-flow relationship in gas pipelines. More accurate for compressible flow with significant pressure drop. Standard method per GPSA.
Atmospheric Pressure: AGA method calculates from elevation using barometric formula (valid <36,000 ft). For critical applications, use site-specific atmospheric data.
Pressure Relationships: Absolute Pressure = Gauge Pressure + Atmospheric Pressure. Calculations use absolute pressures to ensure accuracy.