A volumetric flow meter is an instrument that measures the volume of fluid flowing through a measurement point within a specified time. It is a common type of mechanical flow meter. It can measure the volumetric flow rate of high-viscosity and corrosive fluids.

How does a volumetric flow meter work?

A volumetric flow meter uses a mechanical measuring element to continuously divide the fluid into a single, known volume, and repeatedly fills and discharges that volume of fluid, accumulating the total fluid volume.

Given the conditions of the flow meter, the volume of the measuring space is fixed. By measuring the number of rotations of the rotor, the cumulative value of the fluid volume flowing through the flow meter can be obtained.

Types of volumetric flow meters

To meet the requirements of various media and different operating conditions in production for flow measurement, various types of volumetric flow meters have been produced, mainly including gear flow meters, dual rotor flow meters, and oval gear flow meters.

1. Gear-type volumetric flow meter The oval gear flow meter is also called a constant displacement flow meter, or PD flow meter for short. This type of flow meter contains two rotors inside its housing. These rotors mesh directly or indirectly and rotate under the influence of the pressure difference between the inlet and outlet of the flow meter. Through the rotation of the gears, the fluid filling the "measuring space" between the gears and the housing is continuously discharged. By measuring the number of gear rotations, the flow rate of the fluid passing through the flow meter can be obtained. Elliptical gear flow meters offer high measurement accuracy and are suitable for measuring the flow rate of high-viscosity media, but they are not suitable for fluids containing solid particles (solid particles will clog the gears, making flow measurement impossible). The presence of gas in the measured liquid medium will also cause measurement errors.

2. Twin Rotor (Screw) Flow Meter: The twin rotor flow meter is the latest generation of volumetric flow meters, also known as a UF-type flow meter or screw flow meter. It is particularly suitable for light oil, heavy oil, and crude oil with high sand and water content. It can handle a wide viscosity range of the measured liquid. Industrial liquid metering flow meters can provide on-site indication, direct code reading, and can be assigned. It can output electrical pulse signals, which can be transmitted to secondary instruments or computers to form automatic control, automatic detection, and data processing systems.

3. Roots Flow Meter: The Roots flow meter is also known as a rotary impeller flow meter. It is mainly used for measuring the flow rate of large-diameter gas, liquid, and steam media in industrial pipelines across various industries. Roots flow meters can be used for measuring the flow rate of various clean liquids, especially petroleum, and can also be made into flow meters for measuring gases. It has the highest accuracy, reaching 0.1-0.5 class. Its main disadvantages are: large size, heavy weight, high pressure loss, and significant vibration during operation.