Air Compressor Rating

All air compressors and air compressor tools (pneumatic tools) are rated after operating pressure and air flow/air consumption. This way of rating equipment is much like system for rating electrical components.

In an electrical system, e.g. the one you have in your house, the voltage has the same role as pressure has in an air system. So, if your intake cable delivers 110V to you electrical consumers, your consumers must be rated for the same voltage, in the same way pneumatic tools operated by the air compressor must have the same pressure rating as the compressors output pressure. So if the compressor delivers 120 psi the consumer must have an 120 psi rating. If the air compressor tool rating is lower than the air compressors, which is often the case, we simply install a reduction valve upstream of the consumer, much like we would install a transformer to reduce the voltage in an electrical system.

So we now know that the air pressure of a compressed air system, is the same as the voltage in an electrical system. So what is the effect?

Well, the effect of a compressed air system is the air flow. If we think about it for a second, it becomes clear. To create air pressure, you don't have to put a lot of sweat into it. By pressing down on a bicycle pump you generate air pressure and it doesn't take much effort from you either. By if you where to generate an air flow with that same bicycle pump, you would have to start pumping and do a lot more work. It's the same for an air compressor, even small compressors can, and do, generate high air pressures, but if we where to generate high air flow combined with high pressures, you would need a bigger and bigger air compressor as both pressure and air flow increases.

There is at least one crucial difference between air systems and electrical systems. In electrical systems you have a fuse, cutting the voltage to the consumer if the effect demand gets above the rating for the electrical circuit. We do not have this in air compressors, but if the air consumption (effect) becomes greater than the capacity of the compressor, 1 of 3 things will happen:

1. The compressor will run until the consumption falls below the limit of the compressor, at which point it will stop.
2. The compressors motor overcurrent/temperature protection will cut the power to the compressor due to overheating of the motor, stopping the compressor. (some compressors have timers, stopping them if they run for to long).
3. The compressor will break down and stop.