Circular gear flow meters are suitable for small flow rates and compact spaces, while elliptical gears are good at large flow rates and trade settlements – choosing the right model depends on the diameter, medium, and operating conditions requirements. Both are afraid of particulate matter, and filters are essential.

Distinguishing between circular gear flowmeter and elliptical gear flowmeter
Both belong to volumetric liquid flow meters, which rely on the pressure difference between the inlet and outlet to drive gear rotation and calculate the volume flow rate by counting the number of revolutions. However, there are significant differences in the shape of the internal rotor, flow range, and applicable operating conditions.

1. Distinguish the core structure with the naked eye
   Elliptical gear flowmeter (LC type)
   Rotor: A pair of elliptical gears with eccentric meshing, the gear shape is elliptical, forming a crescent shaped measuring chamber.
   Each revolution releases 4 volumes of crescent shaped cavities; Traditionally, there are mechanical wheel headers with large DN specifications, commonly ranging from DN10 to DN200, and larger shell volumes.
   Transmission: In the early days, many were mechanical couplings and also equipped with pulse transmitters.
   Circular gear flowmeter (micro gear flowmeter)
   Rotor: A pair of standard circular involute gears, coaxial meshing, with tooth slots as measuring units, without crescent shaped cavities.
   Single turn pulse count is high, the movement is very compact, mainly with small flow rates, mostly with threaded small diameters (mostly DN4-DN15), mostly with digital/pulse output, and very few mechanical gauges.
   Simple note: Look at the rotor of the movement, oval=duck egg shape; Circular gear=ordinary circular gear

3. How to choose a model
   Choose an elliptical gear flowmeter
4. For oil products, lubricants, resins, heavy oils, and syrups with a conventional diameter of DN10 or above, trade settlement and mechanical wheel reading are required;
5. The medium is prone to solidification and requires jacket insulation;
6. Operating conditions with a flow rate of tens of L/min or above.

Select circular gear flow rate

1. Micro flow rate and micro addition: a few L/h, a few milliliters per minute, chemical ratio, micro addition of additives, laboratory and equipment OEM built-in;
2. Require low flow output pulsation and stable 4-20mA/RS485 remote transmission;
3. The pipeline is small, the installation space is compact, and mechanical meter heads are not pursued.
4. Common Misconceptions
5. Elliptical gears can only have high viscosity, while circular gears can only have low viscosity: both can cover wide viscosity; The main difference lies in the lower limit of flow and caliber. Elliptical gears cannot achieve very low flow rates; Circular gears cannot handle large pipelines and high flow rates.
   Both are volumetric, and the medium containing hard particles will wear and get stuck, so a filter must be installed upstream.

Quick on-site identification tips

1. Model: LC series is generally an elliptical gear; Circular gear multi standard FG, CX, M series micro gear flowmeter;
2. Flow rate: If the minimum flow rate on the nameplate is a few L/h, it is highly likely that the circular gear will be used; The minimum flow rate above a few L/min is mostly elliptical gears;
3. Header: Almost all counters with mechanical character wheels are elliptical gears; Circular gears are basically electronic digital displays.
   If you need, I can help you organize a quick selection checklist and provide it directly to the customer for technical communication.