How does an Inline Flow Switch/Meter Work?
Inline Flow Meter uses the principle of magnet repulsion to isolate water and electricity. When working, the micro switch does not contact the low-temperature metal parts. There is no condensation, and there is no rust or poor contact of the micro switch.
When water flows in the water flow switch and the water flow is set, the magnetic core in the water flow switch is pushed by the water flow to produce displacement. The displacement of the magnetic core drives the magnetic source to produce magnetic control, causing the water flow to switch to output a signal. The signal is input into the equipment control system, and the control system realizes the control effect.
When the water flow rate is less than the starting flow rate, the water flow switch outputs a signal. The control system produces a control effect opposite to the above.
When the water flow rate in the pipeline is greater than the set value, the magnetic core is displaced under the action of the water flow and drives the magnetic source to produce magnetic control, causing the sensor to output a signal. The signal is input into the equipment control system, and after power amplification, the purpose of water flow control is achieved.
When the water flow rate in the pipeline is set, the magnetic core drives the magnetic source back to its position under the thrust of the reset spring. The sensor outputs a “0” switch signal and stops the system.
What is the difference between an Insertion Flow Meter and an Inline Flow Meter?
Insertion flow meter
The insertion flow meter measures the local flow velocity and derives the total flow by inserting the probe into the pipe. The main types include:
Insertion electromagnetic flow meter (for measuring conductive liquids)
Insertion vortex flow meter (for gas and steam)
Insertion ultrasonic flow meter (for liquid and gas, non-invasive measurement)
Advantages:
Easy installation: can be installed without stopping production, suitable for renovation projects.
Lower cost: suitable for large-diameter pipes (DN300 and above), the price is lower than the pipeline type.
Easy maintenance: the probe is detachable for easy inspection and cleaning.
Disadvantages:
Low measurement accuracy: Affected by flow velocity distribution. It is necessary to ensure a sufficient straight pipe section (usually 10D in front and 5D in the back).
Affected by fluid distribution: turbulence or impurities may reduce accuracy.
Inline flow meter
An inline flow meter is directly integrated into the pipeline system to measure the flow rate of the medium in the entire pipe diameter. Common types include:
Electromagnetic flow meter (high-precision liquid measurement)
Turbine flow meter (suitable for clean liquid or gas)
Coriolis mass flow meter (directly measures mass flow, with the highest accuracy)
Advantages:
High accuracy (usually ±0.5%~±1%), suitable for trade settlement.
Good stability, full pipe diameter measurement, not affected by flow state.
Strong compatibility, suitable for high pressure, high temperature or corrosive media.
Disadvantages:
Complex installation: Pipe cutting is required, which may affect production.
High cost: Large-diameter flow meters (such as DN500 and above) are expensive.
