What is A Flow Switch

The flow switch is mainly installed online or inserted in water, gas, and oil pipelines to monitor the size of the water flow in the water system. The output alarm signal is triggered and transmitted to the unit when the water flow rate is higher or lower than a specific set point. The system can make the corresponding instruction action after obtaining the signal.

flow switch

1. Features

1.1 No pressure loss

We have used unique methods to make the probes very small in size so that there is virtually no pressure loss to the fluid. In many cases, the direct replacement of pressure switches will result in a more reliable system with a broader range of applications.

1.2 Fully straight flow lines

The fully straight-through feature is of great importance in many applications. In the production of petroleum, chemical, heavy industry, light industry, bioengineering pharmaceuticals and many other industries. The flow is impeded by the flow switch and can lead to production accidents such as fluid blocking the pipeline.

The FGS series flow switches can monitor the flow online without affecting the flow rate and avoiding production accidents.

JC210 Standard Thermal Flow Switch

1.3. Vast flow range

The flow switches are only sensitive to the flow rate of the fluid. They can therefore be connected to different pipe diameters to monitor different flow sizes, with virtually no limit to the size of the monitored flow.

1.4. Suitable for a wide range of fluid medium

In the RFS flow switch range, the same type of flow switch can be used for gases and liquids such as water and oil. By simply adjusting the knob in the flow switch, the flow of gases, liquids, etc., can be monitored.

1.5. Simple and intuitive indication

The flow switch has a power indication and a flow status indication. We can visually display the current status of the flow in the pipeline.

1.6. High reliability

Using integrated sensing components and control circuits, with no mechanical movement in the sensing section and high-quality relays in the drive section, results in high reliability.

2. Working Principle

When there is water flow in the water flow switch≥ 1.0L/min, the magnetic core in the water flow switch is pushed by the water flow to produce displacement. The magnetic core displacement drives the magnetic source to have the magnetic control effect of making the water flow switch output an “on” signal.

Flow switch YiYu automation selection records the signal into the equipment control system by the control system to achieve control role. For example, when the water flow is less than the starting flow, the water flow switch outputs a “break” signal.

JC200 Flow Switch(2)

The control system produces the opposite of the above control effect. Water flow switch when the water flow in the pipeline is more significant than 1L/min flow, the magnetic core in the role of water displacement and drives the magnetic source of magnetic control so that the sensor outputs a “1” switch signal. The signal is input to the equipment control system after the power amplification to achieve the purpose of water flow control.

When the water flow in the pipeline is less than 1L/min, the magnetic core is driven back to the magnetic source under the action of the reset spring thrust so that the sensor outputs a “0” switch signal to stop the work of the system.

3. The function of the flow switch

Firstly, there is a fluid passage in the flow switch. This passage is inside the housing, and a piston with a permanent magnet is fitted.

During operation, the fluid gives a certain pressure. When the piston is pushed by the pressure difference caused by the fluid flow, the magnetic piston causes a sealing reed switch inside the device. The diameter of the piston determines the starting flow rate.

If the fluid flow decreases, the pressure will change, and the stainless steel spring will push the piston to reset. If the reed switch is actuated, a remote alarm or indication can be made, and it can also be integrated into the automatic control system.

flow switch

The points in figure 1 are input 1, input 2, COM, N/O, and N/C.

  • Input 1: usually the positive terminal of the relay, the + value of the signal, which is located at the top of the solenoid coil that pulls the stylus.
  • Input 2: the negative value of the signal located at the end of the coil winding. Input 2 should always be considered harmful because some relays can only work in one direction.
  • COM: is an abbreviation for common point. In most cases, the negative value of the power to be switched is connected to this. However, if the application uses the same power supply, then Input 2 and COM can be connected. COM is the middle terminal connected to the pin that pulls towards N/C when the power is switched off.
  • N/C: Normally closed short circuit, but when a signal is present, the pin inside the relay is pulled down until it touches N/C. It will connect it to COM.
  • N/O: short for ordinarily open. When the magnet is closed, a small spring is used to keep it in contact with COM. in most cases, N/O is used to turn on the standby indicator, as it opens when there is no power.
  • Contact: not a terminal, but a pin connected COM to N/O or N/C.

If there is a relay and a 9-volt battery, try connecting the + and – pins together, and you should hear a slight click. It is the pin touching the contact. When the power is turned off, another quieter click will be heard, pulling the plug back to N/C.

As in Figure 2, COM is on with N/C when the coil is powered on. When the ring is not powered on, COM is on with N/O. You can see that when the solenoid is on, the magnet pulls the pin toward the N/O contact, and when it is off, the spring pulls the plug toward the N/C connection.

4. Installation

The installation position of the baffle flow switch is generally installed in the pipeline from the pump outlet to the equipment outlet, not in the channel of the pump intake, which will prevent the pump from sucking water usually and the water flow switch from opening, for which particular attention needs to be paid. In addition, the baffle flow switch can be installed horizontally (with the conductor part on top) and vertically.

5. Conclusion

Air-hydraulic models are widely used in industrial automation, machinery and equipment, the air compression industry, refrigeration and air conditioning, and industrial applications.

They are used explicitly in water-cooled welding machines, laser equipment cooling systems, vacuum coating machines, electric furnaces, polysilicon ingot casting furnaces, etc.

The water flow switch magnets are not in the flowing waterways and can be used in sewage systems and work properly.

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