What is a Pressure Switch?

A pressure switch is an electrical device which can be used to monitor the pressure in different applications and environments in different industries.

A pressure switch has a set activation limit; this will depend on the application and will be set by the user. Once the activation limit is reached, the pressure switch will change state, causing a reaction within the circuit. This is different from a pressure transducer which gives an accurate reading of real-time pressure. 

Working Principle of a Pressure Switch

A pressure switch is a relatively simple device; its main purpose is to alert the user that the pressure has altered within a given area or chamber. A pressure switch has one or two ports which are connected to the area requiring measurement, usually via PVC tubing.

In pressure switches which have one port, the pressure enters through the port and will hit an internal diaphragm. When the pressure alters to over or under the set limit of the pressure switch, pre-loaded set springs will be triggered causing the contact points within the switch to either make or break the circuit. A broken circuit will usually cut the power causing the connected device to shut down for safety reasons. A made circuit will raise an alarm for the user to know the limit has been reached.

Some pressure switches have two ports – these work in a similar way although the pressure enters the switch from two different angles and the switch will monitor the difference between them and alert the user if the pressures are different. This is called a differential pressure switch.

Pressure Switch Application Examples

Pressure switches can be used for a wide variety of applications, some example applications are;

·         Monitoring oxygen levels in tanks for medical use

·         Detecting blockages in extractor fans

·         Filtration systems

·         HVAC applications

·         Liquid dispensing in drinks machines

·         Water pumps

·         Gas compressors

·         Aircraft cabin pressure monitoring

·         Pumps and drives

Pressure Switches from Herga

We have our own range of pressure switches at Herga, these are manufactured onsite. Our pressure switches have the following features;

·         Easily adjustable for your application

·         UL approval available

·         Double pole switching available

·         Microswitch options including tag configurations

·         Sensitive

·         Versatile

·         Suitable for long tube lengths

·         Low pressure options available

·         Temperature compensation versions available

Take a look at all of our pressure switches on our website. For more information on our pressure switches or any of the products on our website please contact us.