Fundamentals Of Coriolis Meters For Gas Measurement – aga Report No. 11

Author: Marc ButtlerDownload File

Since the early 1980s, Coriolis meters have gained worldwide acceptance in gas, liquid, and slurry applications with an installed base of more than one million units. Through significant design, enhancements in the early 1990s Coriolis meters have rapidly gained worldwide acceptance in gas phase applications with over 100,000 meters installed worldwide and most notably the publication of the second edition of AGA Report Number 11, Measurement of Natural Gas by Coriolis Meter.

Having the ability to bidirectional measure almost any gas from -400 to +660 degrees Fahrenheit with little to no concern of error caused by flow profile disturbances, pulsations, or flow surges, Coriolis meters are becoming the meter of preference in many applications.

Coriolis is a small to medium line-size technology; currently the largest offering from any vendor for gas applications is a 250mm (10”) equivalent flow diameter.

The pressure drop and flow range of a Coriolis meter draws a direct relationship to the actual flow area through the meter. When comparing Coriolis to other metering technologies; i.e. the flow area trough a turbine meter is the area not displaced by the turbine internals and rotor, the flow area of an orifice meter is that of the orifice diameter. Because of this relationship, a Coriolis meter will typically be one pipe size smaller than a turbine meter and several sizes smaller than an orifice while having similar pressure drops at flowing pressures in the 300 ANSI class and above.

Being a technology without wearing parts, Coriolis meters are immune to flow factor shift as they age. Most recently, resonant modal analysis techniques incorporated into some Coriolis meter designs allowing flow accuracy verification on-line, without disruption in flow, and without visual inspection of the flow element. Overall, Coriolis meters greatly reduce measurement uncertainty and maintenance costs as compared to other gas flow technologies. This paper will discuss the theory of operation, application, maintenance, and provide examples of Coriolis meter application in gas measurement.