Flow control is made fast, easy, and efficient with essential devices called flow switches. Flow switches are also called flow sensors or flow indicators. This article will explain to you how a flow switch works and the different types of flow switches used in various industrial applications. 

What is a Flow Switch?

A flow switch is a vital industrial device for monitoring and regulating the flow rate of gas and liquid substances. A flow switch is also used to control the pressure of liquids, steam, air, and other gaseous matter. It does this through a system, a loop, or a duct. Flow sensors or switches can either be used to monitor the total flow rate continuously or in a given period of time. 

If you analyze it technically, flow meters or a flow indicator may not be a flow switch because flow switches must be able to stop a device or trigger an alarm. If it only ensures flow rate, then it is only a flow meter or a flow indicator. Flow switches are also used to stop/start the flow, trigger an action, and adjust the flow rate based on the preset parameters. This is a true flow switch. 

How a Flow Switch Works 

Getting to know the various components that make up a flow switch is paramount if you want to understand how a flow switch works. A typical flow switch consists of a primary device which can either be a magnetic trigger or a paddle. The primary device is joint to a pipe or a channel where the fluid is passing and is connected to a circuit. The substance that flows through the flow switch rotates or displaces the paddle. After that, a signal reading is sent back to a secondary part of a flow switch called the transducer.

The raw signal is turned into an understandable format by the transducer, which sends it to the transmitter. The transmitter uses the set parameters to adjust a certain behavior, trigger an action somewhere else in the system, or completely shut off fluid flow. Through a particular part of the flow system, a flow switch can be used to control, monitor, or report flow rate. 

A series of actions may be triggered if the flow rate decreases or increases above or below the present parameters. It may trigger an alarm, turning on the pump, shutting parts of a system, or diverting glow. The type of flow switch device used in an application will determine the kind of action taken. The physical paddle component is not found in all kinds of flow switches. Other non-intrusive versions, such as the ultrasonic flow switch, don’t have a paddle. 

Ultrasonic flow meters work by bouncing a signal back off the monitored medium. Ultrasonic types are ideal flow switches when you want to regulate physically damaging fluids, contaminated media, or where the media is hazardous. It is also a great choice flow switch in systems where moving parts are not needed. 

Installation of Flow Switches 

Although there are many types of flow switches, most of them use almost the same principles of installation. Always ensure that there is a sufficient length of pipe in front and behind the flow switch. The length should be about 10x the pipe’s diameter. Wiring flow switches in features that may cause flow rate fluctuations, including narrower or wider sections, near a bend, other fittings, valves, and drains, should be avoided. 


Whenever you are looking for a flow switch or flow switches, Make sure that you consider the right type, size, function, and voltage. Flow switches work very well when matched with the correct application. If you are clueless about which flow meters to go for, ask the manufacturer for assistance. And always research online for reputable flow switch dealers and companies.