The HUALIU V-cone flowmeter (also known as an inner-cone or cone flowmeter) is a new type of patented differential-pressure flowmeter. A V-shaped cone is suspended at the center of the pipe as the throttling element; as the medium flows past the cone, its velocity profile is reconditioned, creating a stable differential-pressure signal upstream and downstream of the cone, from which the flow rate is derived using the principles of energy conservation and flow continuity. Compared with traditional throttling devices such as orifice plates, its unique built-in cone structure widens the measurable flow range and effectively overcomes many limitations of conventional DP flowmeters.

The flowmeter achieves an accuracy of ±0.5%, ±1.0% or ±1.5%, a repeatability better than ±0.1%, and a turndown ratio of typically 10:1 (which can be increased further if required). The flow-conditioning action of the built-in V-cone gives it an extremely low straight-pipe-run requirement — 0–3D upstream and 0–1D downstream are sufficient to ensure measurement accuracy — so that even installation close to single or double elbows has little effect on accuracy, making it easy to install in space-constrained locations. The cone has a smoothly tapered profile with no abrupt transitions, so the β value remains constant over the long term; the instrument is stable over time and generally requires no recalibration.

The HUALIU V-cone flowmeter operates at medium temperatures up to 450 ℃ and a maximum working pressure of 25 MPa, over a wide Reynolds-number range (8×10³ – 5×10⁶). It is suitable for a wide variety of media including water, steam, air, natural gas, nitrogen, coke-oven gas and organic gases, with medium conditions ranging from deep-cryogenic to supercritical states. Its permanent pressure loss is low; the "self-purging" cone design has no stagnant dead zones and does not readily accumulate deposits, while the short vortex formed downstream also acts as a static mixer. The product is available in intelligent integral and remote structures and can be optionally equipped with single-pressure, single-temperature or pressure-and-temperature compensation. It is widely used for process flow metering in the petroleum, chemical, power and metallurgical industries.