The pressure switch is a fundamental component of your air compressor. It performs a very simple yet vital task. A conventional domestic or small industrial air compressor works by drawing in normal air at atmospheric pressure. This air is then compressed by one or more pistons driven by an electrical or petrol-driven motor and the resulting compressed air is stored in a tank known as an air receiver. Once the air in the air receiver has reached its maximum pressure (as defined in the specification of the air compressor) the pressure switch reacts by turning off the air compressor’s motor. As compressed air is taken from the air receiver – to drive air tools, for example – the pressure inside the receiver drops.
The pressure switch detects when the pressure in the air receiver has reached a pre-set minimum threshold and turns on the air compressor’s motor again to in order for more air to be compressed and stored. Air compressor pressure switches work via a system of diaphragms and valves that can become worn or dirty over time resulting in air leaks and loss of pressure. However, a faulty or broken pressure switch does not mean the end for your compressor; replacement pressure switches are relatively inexpensive and straightforward to fit and adjust according to the specifications of your air compressor.