5 Things to Check Before Using a Roots Flow Meter

As a common type of positive-displacement gas flow meter, the Roots flow meter is widely used for metering natural gas, compressed air, and industrial gases due to its stable measurement and high accuracy. However, in practical application, inadequate pre-installation checks can easily lead to issues such as measurement errors, rotor jamming, or abnormal operation. To help users ensure successful operation, we have outlined five essential checks to perform before using a Roots flow meter.

Check if the model and specifications match the operating conditions

Before installing and using a Roots flow meter, first confirm that the instrument’s model, nominal diameter, flow range, pressure rating, and compatible media type align with actual on-site operating conditions. Different gas media, flow ranges, and working pressures impose different requirements on the flow meter. Improper selection can lead to measurement errors or even disrupt normal operation, even if the instrument itself is functioning correctly.
Therefore, always verify the nameplate, factory specifications, and on-site design parameters to ensure the instrument is suitable for the current process conditions.

Check the installation orientation and piping connections

Roots flow meters are sensitive to installation orientation and the quality of piping connections. Before installation, confirm that the flow direction arrow on the meter matches the actual flow direction of the medium to avoid reverse installation. Additionally, check that the upstream and downstream piping connections are secure and that flanges, bolts, and gaskets are properly installed, ensuring there is no looseness, tilting, or misalignment.
Poor piping coaxiality or leaks at the connection points can not only compromise measurement accuracy but also cause gas leaks, creating safety hazards.

Check for impurities and accumulated liquid in the pipeline

Newly installed pipelines or those that have been out of service for a long time often contain residual impurities such as welding slag, iron filings, and dust. If these foreign objects enter the flow meter, they can easily damage the internal rotors, affecting the instrument’s lifespan and measurement accuracy. For gas media, the presence of accumulated liquid or condensate in the pipeline can also cause rotor jamming, leading to abnormal flow meter operation.
Therefore, it is advisable to purge and clean the pipeline before putting the meter into service; connect the flow meter only after confirming the interior is clean and free of significant accumulated liquid. 4. Inspecting Straight Pipe Sections and Installation Environment

Although Roots flow meters generally have less stringent requirements for straight pipe sections compared to certain velocity-based flow meters, it is still advisable to ensure stable flow conditions in the upstream and downstream piping during installation. Avoid placing the meter immediately adjacent to flow-disturbing components such as elbows, valves, or reducers. Additionally, inspect the installation environment for issues such as intense vibration, excessive temperatures, high humidity, or the presence of corrosive gases.
An unstable environment can lead to accelerated mechanical wear, unstable readings, or frequent malfunctions during long-term operation. Therefore, the Roots flow meter should ideally be installed in a location that is easy to maintain and offers a relatively stable environment.

Checking the Condition of the Meter Body and Accessories

Before use, verify the integrity of the flow meter body—including the housing, display, terminals, sensors, and accessories—to ensure there is no damage from transport or loose components. For associated systems such as temperature and pressure compensation, signal output, or remote transmission units, check beforehand that wiring is correct, the power supply is normal, and communication functions are stable.
If issues such as mechanical binding, display anomalies, or wiring errors are detected, they must be resolved before the meter is put into service to prevent data inaccuracies caused by operating a faulty unit.

The stable operation of a Roots flow meter relies on meticulous preliminary inspection and proper installation. By verifying key factors—such as the model, piping configuration, process medium, and the meter’s condition—prior to use, you can effectively enhance measurement accuracy and extend the equipment’s service life. Hefei Yutuo remains committed to providing customers with product solutions and technical support for Roots flow meters, helping to make industrial gas metering more efficient and reliable.