The HUALIU Oval Gear Flowmeter (HL-LC series) is a positive-displacement metering instrument for the continuous or intermittent measurement and control of liquid flow in pipelines. It offers a wide flow range, high accuracy, low pressure loss and excellent viscosity adaptability, and can measure high-temperature, high-viscosity liquids. Easy to calibrate and install, it is widely used for flow metering in the petroleum, chemical, chemical-fiber, transportation, commerce, food, pharmaceutical and healthcare industries.

The instrument consists of a flow transmitter and a counting mechanism. The transmitter houses a measuring chamber with a pair of oval-gear rotors and a sealed coupling, while the counting mechanism comprises a reduction gear, an adjustment mechanism, a counter and a pulse transmitter. The measuring chamber is formed by the oval gears and cover plates, creating crescent-shaped cavities that serve as the metering unit. Driven by the differential pressure between inlet and outlet, the oval gears rotate and meter the liquid crescent cavity by crescent cavity to the outlet; the liquid passed per revolution equals four times the volume of a crescent cavity. The sealed coupling transmits the gear revolutions and rotational speed to the counting mechanism, yielding the total and instantaneous flow of liquid passing through the pipeline. This HUALIU series is equipped with pointer and digit-wheel totalizing devices for direct on-site reading; when fitted with a pulse transmitter and paired with electronic display instruments, it enables remote centralized control of totalized, batch and instantaneous flow. Adding a heat sink or selecting the truncated-tooth oval-gear version allows measurement of high-temperature, high-viscosity liquids.

Because measurement relies on the medium's pressure head to drive the gears and is independent of the fluid flow state, and because the higher the medium viscosity the smaller the leakage through the metering clearances and thus the smaller the leakage error, the HUALIU Oval Gear Flowmeter is especially suited to high-accuracy metering of high-viscosity media. For different liquid media (acids, alkalis, salts, organic solutions, etc.) it can be manufactured from cast iron, cast iron with aluminum gears, cast steel or stainless steel. Note that this product is not suitable for fluids containing solid particles, and entrained gas in the medium will also cause measurement error.