Thermal Flowmeter Auto Switching Feature Allows Oil & Gas Company to Accurately Measure Flow Rates

2015 Flow Control Innovation Award Winner:
Thermatel TA2 Auto Switching — By Magnetrol International

A leading oil and gas company required a gas flow measurement technology that could accurately measure natural gas flow rates at its compressor stations. One of the applications of interest was measuring vent gas emissions from the packing systems of compressors. This application not only requires flow measurement at very low flows and low pressures, but the capability of achieving high turndown as well. Emissions can tend to increase over time as components wear, thus increasing the potential flow rates.

The turndown is essentially the range that the flowmeter is accurate within. Most thermal mass flowmeters offer 100-to-1 turndown, which is a drastic improvement over most technologies such as differential pressure, but certain applications demand greater. This presented an improvement opportunity for the Magnetrol Thermatel TA2.

Since the TA2 thermal flowmeter is capable of holding multiple calibration curves, users requested added functionality of these features. To meet this need, MAGNETROL developed Auto Switching to fully utilize two distinct calibration curves. Auto Switching automatically alternates between a low flow curve and a high flow curve to maximize data in the customer flow range and extend the turndown. This ensures optimal performance at both low flows and the abrupt high flow (upset) condition or an increase in flow over time due to degradation of components.