Metal Tube Rotameter Mechanical Pointer Gas Liquid Micro Flow

The metal float flowmeter belongs to the variable area flowmeter. Its working principle is based on the balance between fluid dynamics and the gravity (or buoyancy) of the float.

• A permanent magnet is embedded in the float inside the tube.
• Outside the instrument, at the position corresponding to the float, there is a follower magnetic steel (or magnetic coupling system) connected to the pointer.
• When the float moves up and down with the change of flow rate, the magnet inside it will drive the external follower magnetic steel and pointer to move synchronously through the non-magnetic metal tube wall, thereby indicating the flow rate.
• This non-contact transmission method completely avoids dynamic sealing, ensuring no leakage and safety.

• Robust structure, resistant to high pressure and high temperature: Compared with glass tube float flowmeters, the metal tube body can withstand higher pressure and temperature, making it suitable for harsh industrial environments.
• High safety: No risk of glass tube breakage, making it suitable for measuring toxic, flammable, and explosive hazardous media.
• Intuitive on-site indication: Usually equipped with a pointer and dial, allowing for convenient on-site reading of flow.
• Small and constant pressure loss: Throughout the measurement range, the pressure loss is small and relatively stable.
• Wide range ratio: Typically up to 10:1, providing a wide measurement range.
• Optional remote transmission output: Can be equipped with a transmitter to convert the float position into a standard signal (such as 4-20mA) and transmit it to the control room.
• Applicable to various media: Can measure liquids, gases, and steam.

• Petrochemical industry: Process flow monitoring of various oil products and chemicals.
• Power industry: Measurement of water supply, fuel oil, air and other flows for boilers.
• Pharmaceutical and food industry: For occasions with high hygiene requirements, sanitary connections and polishing treatment can be adopted.
• Water treatment: Measurement of the addition amount of chemical agents.
• General industry: Flow measurement of public utilities such as compressed air, steam, and cooling water.

vs. Glass tube float flowmeter: Metal tubes are safer, more robust, and can withstand high pressure and high temperature, but they are not as intuitive as glass tubes and are more expensive.

vs. Orifice plate flowmeter: Metal float flowmeters have less pressure loss, intuitive readings, and are easier to install, but orifice plates can withstand higher temperatures and pressures and have no moving parts.

vs. Electromagnetic flowmeter: Electromagnetic flowmeters can only measure conductive liquids and require power supply, but they have no pressure loss, high accuracy, and are not affected by density and viscosity.

Metal float flowmeters are medium-precision flow instruments with a simple principle, sturdy structure, and intuitive reliability. They play the role of "on-site monitors" in industrial processes, and are a very economical and practical choice especially when local indication or measurement of small flows and medium-low pressures is required. The key to their successful application lies in vertical installation and correct selection and calibration based on the actual properties of the medium.