AGA-3 is a natural gas measurement standard defining equations for calculating gas flow through orifice plates. It is the primary standard for custody transfer orifice measurement in North American pipelines.

What compressibility method should I use?

AGA-8 Detail is the most accurate and preferred for custody transfer. AGA-8 Gross is acceptable for less critical applications.

Beta ratio is the orifice bore diameter divided by pipe internal diameter. AGA-3 specifies acceptable ranges (0.20-0.75). Totalflow calculates it from the entered dimensions.

AGA-3 Orifice Meter Configuration on ABB Totalflow

Quick Answer

AGA-3 orifice meter configuration on Totalflow involves creating an AGA-3 application in PCCU32, entering meter tube and orifice plate dimensions, assigning pressure and temperature inputs, configuring gas composition (fixed or live from gas chromatograph), and selecting the compressibility calculation method (AGA-8 Detail preferred for custody transfer).

Configuration Steps

Create AGA-3 application in PCCU32
Enter pipe ID, orifice bore diameter, materials, and tap position
Assign DP, static pressure, and temperature input channels
Enter gas composition (mole % for each component) or link to live GC
Select base conditions (14.73 PSI, 60°F standard)
Select compressibility method (AGA-8 Detail recommended)
Configure alarm limits (high/low DP, pressure, temperature)
Set archive intervals (hourly, daily)
Verify calculated flow rate against hand calculation

Gas Composition

Gas composition directly affects compressibility (Z-factor), heating value, and specific gravity. Live composition from a gas chromatograph provides the most accurate measurement for custody transfer.

Compressibility Method

AGA-8 Detail — Most accurate, preferred for custody transfer
AGA-8 Gross — Acceptable for less critical measurement
NX-19 — Legacy method for backward compatibility

Frequently Asked Questions

AGA-3 Orifice Meter Configuration on ABB Totalflow

Key Takeaway