The turbine flowmeter is considered one of the main traditional flowmeter technologies, as differential pressure types and positive displacement meters. They still are a favorite device used to measure gas flow, particularly for a clean, medium-to-high steady flow of low-viscosity fluids. The turbine meter measures volumetric flow based on fluid flowing past a free-spinning rotor, with each revolution agreeing with a specific volume of fluid. Turbine meters are used for the measurement of liquids as well as natural gas flow.

Advantages

The turbine flow meter has certain cost advantages over other natural gas flow measurement options, particularly those reluctant to invest in new technology. They are also significantly less expensive, particularly in large pipe sizes than the ultrasonic meter and the Coriolis meter. There are additional cost advantages over DP meters, particularly in applications where a single-turbine meter can replace several DP meters.

The meters have high turndown and accuracy at a mid-to-high flow and medium rangeability at high pressure. An electronic output is also available. Additionally, this natural flow totalizer has reasonable industry acceptance.

Limitations

Certainly, the turbine meter has moving parts, which is always a limitation, and the user needs to consider the cleanliness of the gas. Some turbine meter manufacturers have improved the internal components to minimize these concerns, but having moving parts is still a disadvantage. Other improvements by manufacturers have included reduced pressure drop, bidirectional flow, and self-lubrication.

The meter requires initial laboratory flow calibration and relatively high-pressure loss. There is also the chance of damage because of over-speeding the meter.