To begin with, as when choosing other equipment, whether it be a welding machine or a generator, you should determine the range of tasks and parameters for the compressor, and not be guided by the primitive judgments of “I would be more powerful” or “the cheapest”.
The main parameters when choosing a compressor
When looking for air compressors for sale, first, it is worth paying attention to such indicators as:
- maximum pressure.
We will analyze in more detail what these characteristics are:
Productivity (l / min) – this indicator determines the number of liters of compressed air at the suction that the compressor can catch in 1 minute. This value can often change due to differences in air temperature, as well as on the configuration of the model. Therefore, it is always worth choosing a compressor with a 30-50% margin in productivity, compared with the declared value by the manufacturer.
Power (kW) – a value that reflects the potential to perform work. Accordingly, the higher the engine power, the faster the compressor will cope with the task. It is important to understand that in practice the actual power is always less than the declared power. Therefore, here you should choose a compressor with a small margin for this parameter (about 30%).
The maximum compressor pressure (Bar) is the force with which the compressor can compress air. This value is one of the main indicators, with the help of it it is determined which tool the compressor can interact with. Here, as well as in the example with the above parameters, it should be understood that the pressure during the working cycle can fluctuate, for example, if the declared pressure is 10 Bar, it can fluctuate from 10 to 7.
Now let’s move on to ergonomic indicators, as For many customers, the dimensions of the compressor and its mobility are important . In this case, reciprocating compressors are one of the most compact, and the most convenient and easily portable are oil-free compressors, the models of which do not have a receiver.
Many models (both piston and screw) are equipped with wheels and handles for transportation.
As intended, compressors provide compressed air to a pneumatic tool. Therefore, when choosing a compressor, you need to proceed from the needs of your pneumatic tool. For example, spray guns can have a pressure of 4 Bars, but a sandblast gun and grinder need at least 6.
It is also important to determine how often you will use the compressor. If you operate it no more than once every six months, then it makes no sense to buy, there is simply no professional model.
Do we need a receiver? A receiver is a container in which compressed gas is stored. When the receiver is full, the equipment is turned off and compressed gas is supplied from its storage tank. Therefore, the service life of the compressor with the receiver is slightly higher, but for non-intensive “rare” tasks, this option can be completely dispensed with.
Piston or screw compressor, coaxial or belt type?
For a short repair work at home or in the garage, a piston oil compressor is quite suitable .
The main advantages of this type of equipment:
- small dimensions;
- productivity is from 200 to 500 l / min;
- automatic lubrication of related parts;
- The optimum ratio of price and quality.
- maximum pressure 8-10 bar;
- power 1.5-2.2 kW;
- receiver volume 24-200 liters;
- piston oil is the most common type of compressor.
Coaxial compressors are also often used in everyday life, in which the engine is directly connected to the coupling, but they have several disadvantages, namely:
- high noise and vibration.
- shutdown frequency;
The duration of their work is not long, on average, every 5 minutes this equipment needs rest. This, of course, slightly reduces performance. If you need a compressor that will work for a long time and it will have a high degree of “survivability”, then piston compressors with a belt drive will be a good solution for small workshops and industries . In terms of dimensions, they are superior to coaxial ones, but thanks to their device, they last longer and are less prone to breakage.
- increased working resource;
- maximum pressure 10-15 bar;
- power 1,5-3 kW;
- receiver volume 24-500 liters;
- productivity is 250-2000 l / min (at two-stage compressors);
- improved cooling system;
- enlarged oil sump;
- engine overheat protection.
The disadvantages of belt compressors, like coaxial ones, are a rather high noise level and the presence of oil particles in compressed air.
An admixture of oil in the air is mandatory for use with most pneumatic tools, as this provides automatic lubrication of parts. But the presence of oil in the air supplied to the spray gun can only worsen the result of work. Therefore, we recommend the use of oil-free compressors for paint work, as well as in the food, chemical, paper industries .
Oil Free Benefits:
- easy start-up even at low temperatures;
- productivity is 180-230 l / min;
- maximum pressure 8 bar;
- clean air without impurities;
- small dimensions and weight;
- forced air cooling;
- receiver volume 24-50 liters.
The oil in these compressors flows through a separate channel and does not come into contact with compressible gas.
The disadvantages of such equipment:
- small work resource
- smaller range of applications (not all pneumatic tools can work without additional lubrication)
If you need trouble-free operation, we advise you to look at screw compressors . Many manufacturers produce fully equipped plants. They consist of the compressor itself and additional elements (dehumidifiers, filters, frequency controllers).
Advantages of screw compressors:
- high productivity (different models produce from 500 to 12,000 liters of compressed air per minute);
- maximum pressure 6-15 bar;
- power 2.2-90 kW;
- low energy consumption;
- reduced noise and vibration;
- the possibility of uninterrupted operation for several work shifts.
If the presented recommendations are not enough for you, then you can always seek the advice of our managers.