The metal tube float flowmeter (metal rotameter) is a flow measuring instrument based on the variable area principle. Its core components include a metal tapered tube, float, positioning rod and indicator. When fluid flows upward through the tapered tube, it lifts the float. The float position varies with flow rate — higher flow leads to higher float position. This position is converted into flow reading via magnetic coupling or mechanical transmission. It is widely adopted in petroleum, chemical, metallurgical and pharmaceutical industries to measure liquid, gas and steam flow. Suitable for medium & low flow and pipe size DN15-DN200, especially for corrosive media or fluids under pressure.
Product Principle
It consists of flow sensor and flow indicator. The float is vertically mounted inside the tapered measuring tube and can freely move up and down under fluid force. A high-performance permanent magnet is built inside the float. The surrounding magnetic field changes as the float moves. When flow is stable and the float reaches dynamic balance, the magnetic field stays steady. The flow indicator connected to the tapered tube receives the float’s magnetic signal in non-contact mode by magnetic transmission. The flow value is displayed on the scale. LCD screen can show instantaneous and cumulative flow, with optional 2-wire 4-20mA output or HART protocol.
