Flow switch: How it works and their types

A flow switch is the Proteus industry’s device that people use to measure the flow of gasses, liquids, or steams through a designed tube or channel. They can send an alert or alarm to the users when they sense any leak, thus helping in protecting various industrial properties. Below is an image example of a flow

Unlike flow meters, where the user must check the measurement readings by themselves, flow switch records and shows the measurement readings making it easy for users to operate. They help in activating the volume of substances at a higher or lower temperature. The flow switch detects any danger or blockage that can destroy the pump and sends a signal to the user.

How flow switches work

For a flow switch to work, the user should join the paddle to activate the switch flow. By doing this, the liquids and gasses passing through the tube will dislocate the paddle. This makes the switch in the circuit shut off because of the variation in volume and pressure, i.e., when the book is high or low. The diagram below shows how a flow switch operates.

The flow switch device goes around the paddling machine in a circular motion for two or more trips inside the pump or water tube. This will show whether the switch is ready for the user to turn it on or off. It then gives an alarm or signal about any damage or occurrence of an activity that is likely to destroy the pump.

You should closely examine the flow switch to know whether it needs to be adjusted or not when the volume is low or high. The ability of the flow switch to measure and record the readings makes them suitable for various applications such as;

i)Supplying air or other gases in different media.
ii) Treating water systems in different water industries.
iii) Heating different types of ducts.
iv) Helps in blending systems mostly in food industries.
v) Helps in air conditioning through cleaning rooms or enhancing ventilation systems.
vi) Treating or chlorinating swimming pool water and warming it.
vii) It ensures the transfer of liquids or fluids systems.
viii) Flow switch helps in cooling industrial machines since it can activate and deactivate the motor.
ix) A flow switch helps to trigger and turns on an electric fire alarm.

Types of flow switch

We can place the classes together to measure liquids or gasses in pipes or a water pump. There are various types of flow switches grouped by the type of measurement or the media of the flow. Below are the main types of flow switches.

i)Volumetric flow switches

These are common types of flow switches that people use to measure the flow of gases and liquids passing through a specific channel. The user can measure the volume in each unit time and get the required measurement per minute in cubic feet. Many companies use these types of flow switches when controlling water flow. The image below shows a volumetric flow switch.

ii) Gas flow switches

Gas flow switches enhance the measurement of the flow of steam and air. They can measure the rate at which air or moisture flows in a tube or pipe and indicate the reading at the sensor. Many industries and companies use it in their machines. For example, in HVAC applications or different companies where people use it for air ventilation systems. Here is how gas flow switches look like;

iii) Velocity flow switches

Velocity flow switches are flow switches that people use to measure a flow rate over moving media. In most cases, people always do the measurement and set the flow switch to show the readings in velocity feet for every minute. Below is an image diagram of a velocity flow switch.

iv) Liquid flow switches

Liquid flow switches are flow switches that people use to measure the media of various substances such as chemicals, water, slurries, and lubricants. People mainly use them to control or monitor the flow of different meanings and lubricate some motor engines.


Other types of flow switch for specific use are;

i)Doppler flow switch

Another name for a Doppler flow switch is an ultrasonic flow switch. It works by alerting the user on a specific flow change.

ii) Vane operated flow switch

This type of flow switch pushes the liquid in the paddle and accelerates the mechanical magnets making the button circulate for some trips.

iii) Variable area flow switch

This type of flow switch activates the circuit making the flow entries in the port, thus increasing the magnetic pressure of the poppet. The button turns off when the pressure reaches the set level.


Flow switches are suitable to measure, monitor, and detect any issue that may cause equipment damage during a liquid, gas, or steam flow. Therefore, it is known to protect various pumps, tanks, pipes, e.t.c in multiple industries or companies.

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