The HUALIU Roots Flowmeter is a high-accuracy positive-displacement metering instrument for the continuous or intermittent measurement of liquid flow in pipelines, and is one of the classic positive-displacement flowmeter products. It features high accuracy, good reliability, light weight, long service life and convenient installation and use. It is widely applied in the petroleum, chemical, power, metallurgy, transportation, food processing, pharmaceutical, defense and commercial trade sectors, providing precise metering of petroleum and petroleum products, chemical solutions and other fluids.

The flowmeter mainly consists of three parts—the measuring chamber, the sealed coupling and the counter—and can indicate totalized and instantaneous flow on site. When the measured liquid flows through the measuring chamber, a differential pressure forms between the flowmeter inlet and outlet; the lobed rotors are driven to rotate by this differential pressure, and a pair of drive gears fixed on the rotor shafts keeps the two lobed rotors in continuous synchronous rotation. The liquid is continuously discharged from the measuring chamber, and the volume of liquid passed per pair of rotor revolutions equals four times the volume of the measuring chamber. This is transmitted through the sealed coupling and reduction mechanism to the counter, indicating instantaneous and totalized flow.

The HUALIU Roots Flowmeter offers high measurement accuracy, with a basic error generally reaching ±0.2%~±0.5% and up to ±0.1% for special requirements. Its characteristics are essentially unaffected by the flow state and Reynolds number, and the turndown ratio is typically 5:1~10:1. The digit-wheel counter totalizes the fluid without any external power source and uses a dual display, one of which can be reset to zero, making it convenient for non-continuous metering applications. The metering components are non-contact and wear-free, giving a long service life. When a pulse transmitter is added to the counting mechanism, it becomes a Roots flowmeter with transmitter; paired with a display instrument or a computer system, it enables remote automated measurement and control of batch, totalized and instantaneous flow.