What is Pressure Switch all About?

Pressure switches are widely used in different industrial fields, especially those related to pumping systems, HVAC, instrumentation systems, compressed gas systems, etc. It is a mechanical or electronic device that operates when the pressure of air, fluid, or gas reaches the threshold. The tridelta pressure switch consists of pistons, bourdon tubes, diaphragms, membranes, etc., and moves when an industrial system exerts pressure.

Working mechanism

A standard pressure switch consists of a piston, where one of its sides is subjugated to the pressure of the fluid. The atmospheric pressure is on the other side of the pressure switch. The force exercised by the pressure of the fluid is forestalled by a preloaded spring force. The surface area in contact with the fluid and the spring is designed meticulously. This is important to ensure that the piston moves only when a certain pressure is exerted. The switch’s spring is pre-shut by the threshold screw, which gets adjusted to higher or lower pressure.

Operating units

A tridelta pressure switch consists of two operating units.

  1. Cut-in pressure
  2. Cut-out pressure

In industries that utilize compressor and pump systems, the pressure switch is triggered when the fluid pressure is below a set level. This helps the motor of the compressor or pump system to start, which helps the system to reach the average level. When the fluid pressure is above the specific set level, the pressure switch doesn’t get deactivated immediately. There is a lagging effect that suppresses sudden tripping and deactivating of the switch. This enables the pressure to accumulate until the highest pressure level is reached. When a higher cut-out is reached, the pressure switch becomes inactive.

Applications for pressure switches

Pressure switches are widely used in different control systems of industries. Some of the common applications include:


Pressure switches are used as a safety function in HVAC units like furnaces. The pressure switch turns off the furnace when negative pressure is detected, usually yielded by a draft-inducing motor. Furthermore, pressure switches also help to identify leaks while examining gas pressure.

Pumping units

Maintaining water levels in a reservoir is vital. Thanks to pressure switches that activate and deactivate the pump as required and help to maintain the right water level. When the water pressure falls below a set point or reaches the set point, pressure switches handle the pumping operation.

Compressed air units

The presence of pressure switches helps to turn on and turn off the air compressor units at the setpoint.

Two types of pressure switches

When considering pressure switches, one will be encountered two types.

  • Electronic pressure switches don’t require propulsion from pressure-detection units to function. They are known to function via the use of electrical potential and resistance.
  • Mechanical pressure switches are used to assess the pressure of air, fluid, and gas. When the set-point is reached, mechanical pressure switches activate or deactivate.


The models of tridelta pressure switch units are used extensively in industries. Several industries also make use of pressure switches as an additional safety measure. For instance, during a power cut, the pressure switch is the backup to propel when the threshold is reached.

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