How Air Compressor Works with Piston


While you can easily find a large variety of them these days, things were not as good in past when air compressors were seldom seen in homes, factories and workplaces. In fact, air tools used in shops were powered by large and expensive centralized system of belts, wheels and shafts.

Because of their complexity, size and maintenance cost, no one would have thought to acquire those power generation systems. However, things have gone smarter, simpler and easier. Air compressors can be found on many places, like factories, tire shops, workshops, even homes.

There are quite a few professions in which air compressors have been treated as a basic necessity. You need it for power tools such as, grinders, staplers, spray guns, nail guns, impact wrenches, sanders, painting tools and more.

Unlike past, these handy machines are available on hardware stores, web stores, and home depots everywhere around the world. They’ve gone better in terms of size, functionality, less maintenance, environment friendliness, portability and energy-saving.

So, if you’re interested in buying the best air compressor for your home or workplace, you should start by knowing how this system works. This article will help you realize what kind of air compressor suits your puspose.

Basic Piston Phenomenon

The function of air compressor is based on simple principle. The air compression takes place when the air is pressurized and its volume decreases. If you’re aware of the air compressor mechanism, you must have agreed to the fact that air compressors consists of either rotating impellers or reciprocating piston.

Although, there are air compressors that use rotating impellers to create air pressure, yet most commonly used air compressors utilize reciprocating piston to achieve this phenomenon. To understand the functionality of compression with reciprocating piston, you need to know how internal combustion engine works. Both have many things in common.

Components of Air Compressor with Piston

The compressor with reciprocating piston consists of the following:

  • Crankshaft
  • A piston
  • Cylinder
  • Connecting rod
  • A valve head

Modern-day air compressors generally consist of air tanks for storing compressed air. This is to maintain and control air pressure at a certain level while you power various air tools.

Every compressor cylinder has a valve head at its top that comprises of suction valve and discharge valve. These valves are located on top of the metal plate and are basically metal flaps.

Mechanism of Air Compressor with Piston

Basic air compressors work with the help of external power; gas or electricity. It depends upon the model you have; whether it works on electricity or gas.

  • Inside the cylinder, as the piston moves down, it creates a vacuum in the space above it. This creates a difference between the pressure inside and outside the cylinder and opens the suction valve.
  • The air enters the vacuum space and gets compressed by the piston coming back upwards. The compressed air then forces its way through to the discharge valve and moves to the air tank. As a result the pressure inside the tank increases.

Mechanics of Dual-Piston Compressor

The rule varies from machine to machine but the basic principle remains the same. Dual-piston compressors are quite common these days, and they have the same functionality as those with single piston.

The only difference between single-piston and dual-piston compressors is, dual-piston compressors have two strokes per revolution. In general, dual piston compressors use two-stage compression in which one piston is responsible to compress air and move it to second cylinder with relatively greater pressure.

But there is always a threat of tank explosion, so dual-piston compressors have a special switch that disconnects power supply as soon as the internal pressure attains maximum limit (around 130psi). You can calibrate the air pressure of your compressor with that of the air tool attached with the help of the regulator and gauges attached to it.

The regulator and additional gauges help you measure the pressure in the line and inside the tank. If switch doesn’t goes off automatically, you can release the safety valve to reduce the pressure manually.

Along with the safety valve, you can also see the unloader valve. You can use unloader valve to release air when the compressor is not in use.




You also need to realize how important it is to lubricate your air compressor. To do that, you need to understand how to lubricate your compressor.

There are two kinds of compressors based on lubrication, discussed as below:

  1. Oil-lubricated pump: they have oil bath which is responsible to lubricate the bearings and internal walls of cylinder. Piston rings help prevent air from mixing with oil to large extent, but there’s always a risk of air-oil mixture that may cause performance issues.

Oil-lubricated compressors can be used with power tools that need lubrication anyways, on places where small oil spots can be compromised.

  1. Oil-free pump: they consist of permanently lubricated bearings, unlike those in oil-lubricated pumps. Therefore, they require minimal maintenance and lubrication.

If you’re using power tools for woodworking, painting or finishing, you may want to use oil-free compressors, in order to avoid oil stains.


An air compressor is a handy device that uses compressed air to power your tools in the absence of power sources like gas or electricity. While our air compressor reviews will surely help you by the best product, you also need to learn how to maintain these gadgets. Therefore, it is advisable to learn how air compressor works and how you can maintain it by using the manufacturer’s manual to good effect.


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