Types of pressure switches

Pressure switch or pressure controller is one of the most common control equipment in the industry and other items such as the construction of pressure-dependent fluid equipment that can be used to control the pressure applied to a fluid such as liquids and gases. The simplest form of a pressure switch is to be able to open and close a contact while increasing the pressure drop beyond a certain limit.

Pressure switches are designed from the point of view of application in electromechanical models and electronic or digital models, which are explained below.

Electromechanical pressure switch:

The basis of mechanical pressure controllers is similar to hand pressure gauges and generally consists of the following models:

Diaphragm switches : Welded metal seals are used to stimulate the switch. They have an operating pressure of up to 150 pressure phenomena and an accuracy of ± 0.5%.

Bourdon pressure switches : It consists of a C-shaped tube or Bourdon, which is used to move the switch to stimulate and move the switch. Operating pressure is from 50 to 18000 psi and accuracy is 0.5%

Another type of pressure switch or pressure switch is a diaphragm piston with an elastic diaphragm that operates on a piston. The piston then activates the switch. Their working pressure is from vacuum up to 1600 psi and accuracy ± 0.2%.

Piston switches are another type that use a piston to activate the switch. Their operating pressure is 12000 psi and their accuracy is ± 0.2 و and they are mostly used in the hydraulic industry.

The differential pressure switch or pressure difference may have a diaphragm, metal or elastomeric sensor. They have two pressure inlets, one for up and down pressure. The sensor detects the pressure difference between the two sources and activates the switch.

Another type of pressure controller is the solid state and digital type , which can have one or more switching points . Pressure switches of this type not only control the control circuit by opening and closing the circuit at high or low pressure, but also in models including digital display and analog and digital output. Most current models are fully programmable and can communicate with a PLC or computer. Solid state pressure switch has a wide range of operating pressure and frequency response. They are highly resistant to impact and vibration with an accurate resistance of ± 0.25%. Compared to electromechanical pressure switches, their lifespan is very long.