A rotary piston flowmeter is a type of flowmeter that accumulates the volume of fluid by counting the number of rotations of the rotary piston within the metering chamber.

1. Extremely high measurement accuracy: The accuracy is usually within ±0.2% to ±0.5%, making it one of the most accurate flowmeter types, especially suitable for trade handovers.
2. Insensitive to viscosity changes: The measurement principle is based on volumetric displacement and is minimally affected by fluid viscosity. The higher the viscosity, the smaller the internal leakage, and the better the performance. It is an ideal choice for measuring viscous media such as heavy oil, crude oil, lubricating oil, and asphalt.
3. Wide measurement range: It can reach 10:1 or higher.
4. Direct mechanical measurement without external power (basic model), ensuring high reliability.
5. Low starting flow rate, capable of accurately measuring low-speed flows.

1. Petroleum and petrochemical industry (core market): Retail measurement of gasoline and diesel at gas stations (core of fuel dispensers); trade handover of fuel oil, lubricating oil, and base oil at oil depots; process measurement of heavy oil and residual oil in refineries.
2. Chemical industry: Batch shipment or process batching of resins, solvents, additives, and high-viscosity chemicals.
3. Food and oil industry: Filling and measurement of viscous foods such as edible oil, syrup, chocolate, and honey.
4. Ship bunkering: Key measurement equipment for fuel oil bunkering of ships, requiring high precision and reliability.

Rotary piston flowmeters are the "precision measurement experts" in the family of positive displacement flowmeters, especially in the field of trade measurement for "high-viscosity clean liquids", where they have established an unshakable position.