The HUALIU Metal Tube Rotameter (metal-tube variable-area flowmeter) is a variable-area flow instrument based on measurement of the float position. Featuring an all-metal structure and a modular design concept, it is compact with low pressure loss, a wide turndown ratio and easy installation and maintenance. It provides reliable flow measurement and process control of small flows, low flow velocities and various demanding media under complex, harsh operating conditions, and is widely used in the petroleum, chemical, metallurgy, power, environmental protection and pharmaceutical industries.

Its operating principle is as follows: the measured fluid enters from the lower end of the tapered measuring tube and impinges on the float placed inside the tube, producing a force that varies with the flow rate. When this force balances the effective weight of the float in the fluid, the float stabilizes at a corresponding height; the float position corresponds one-to-one with the flow rate, from which the flow value is read. The HUALIU Metal Tube Rotameter uses a non-contact magnetic-coupling angular detection sensor together with a microprocessor system to provide dual-line LCD display of instantaneous and totalized flow, 4~20mA remote-transmission output, pulse output and upper/lower limit alarms, and offers intelligent features such as power-loss protection and data backup and recovery.

According to the user's process flow direction, the product can be supplied in various installation forms including bottom-in top-out, top-in bottom-out, side-in side-out, bottom-in side-out, threaded connection, clamp connection and horizontal installation. Standard, high-temperature, PTFE-lined anti-corrosion, jacketed, and intrinsically-safe/explosion-proof types are available, offering resistance to high temperature, high pressure, vibration and corrosion to meet diverse on-site application requirements.