How to choose a compressor for your spray gun

A ‘spray gun’ is an indispensable piece of equipment for efficiently and cleanly painting everything. A spray gun is painting equipment that uses compressed air to spray paint in mist form. Therefore, a compressor, which produces the necessary compressed air, is an indispensable piece of equipment when using a spray gun. Since spray guns and compressors are sold separately, it is important to know well in advance what combination is best to purchase. This article will explain the key points on how to select a compressor when using a spray gun.

Three indicators for compressor performance

Indicators of compressor performance are as follows.

Compressor output

This is the so-called horsepower of the compressor and is expressed in units of kW or PS.

Air pressure

It is expressed in units such as MPa (megapascal), which is a unit of pressure, and shows the compressor's pressure characteristics.

Air discharge volume

This is the volume of air discharged from the compressor and is displayed in L/min, a numerical value indicating the volume of air that can be created per minute. However, the value listed as the amount of air used is slightly different from the actual amount of air discharged from the compressor. If the compressor specifications specify a standard condition (NL/min, Nm3/min, etc.) for the air consumption, multiply this value by a factor of 1.079 to calculate the amount of air discharged from the compressor.

These are three indicators for compressor performance. When selecting a compressor for a spray gun, which of these performance indicators should we focus on?

Select a compressor based on the characteristics of spray guns

In the first place, to spray paint mist using a spray gun, a ‘certain amount of compressed air’ is needed, which is required for spray guns. The amount of compressed air required depends on the application, model and function,etc. of the spray gun to be used, so it is necessary to check in advance. The most important factor in confirming whether or not the required amount of compressed air can be supplied to the spray gun is the ‘air discharge volume’ of the compressor.

Compressors create compressed air by compressing air, and the amount of compressed air varies depending on the model. Therefore, a compressor that is suitable for a spray gun means a compressor that can discharge more air than the spray gun requires. Conversely, if the amount of air discharged from the compressor is less than the air consumption of the spray gun, the spray gun cannot be used.

Compressor air tank utilization and precautions

Even if the compressor's air discharge volume is less than the amount of air used by the spray gun, if the compressor's air tank itself is large enough, it may somehow be used until the compressed air in the tank is used up. However, this type of usage requires the air tank to be operated at full capacity each time, which places a burden on the compressor and may cause it to break down, as well as an unnecessary increase in power consumption. Therefore, when purchasing a compressor to match the spray gun, it is recommended to purchase a compressor capable of discharging more air than the air consumption of the spray gun.

The combination of the spray gun and compressor is very important, and if you purchase a compressor without knowing these points, you will not be able to achieve the full performance of the spray gun, and in the worst case, you may not even be able to use it. Therefore, when purchasing a compressor for a spray gun, pay close attention to this air discharge volume.