Air compressors have many uses, including: supplying high-pressure clean air to fill gas cylinders, supplying moderate-pressure clean air to a submerged surface supplied diver, supplying moderate-pressure clean air for driving some office and school building pneumatic HVAC control system valves, supplying a large amount of moderate-pressure air to power pneumatic tools, such as jackhammers, filling high pressure air tanks (HPA), for filling tires, and to produce large volumes of moderate-pressure air for large-scale industrial processes (such as oxidation for petroleum coking or cement plant bag house purge systems).
Most air compressors either are reciprocating piston type, rotary vane or rotary screw. Centrifugal compressors are common in very large applications, while rotary screw, scroll, and reciprocating air compressors are favored for smaller, portable applications.
There are two main types of air-compressor pumps: oil-injected and oil-less. The oil-less system has more technical development, but is more expensive, louder and lasts for less time than oil-lubed pumps. The oil-less system also delivers air of better quality.
Air compressors are designed to utilize a variety of power sources. While gas/diesel-powered and electric air compressors are among the most popular, air compressors that utilize vehicle engines, power-take-off, or hydraulic ports are also commonly used in mobile applications.
The power of a compressor is measured in HP (horsepower) and CFM (cubic feet per minute of intake air). The gallon size of the tank specifies the volume of compressed air (in reserve) available. Gas/diesel powered compressors are widely used in remote areas with problematic access to electricity. They are noisy and require ventilation for exhaust gases. Electric powered compressors are widely used in production, workshops and garages with permanent access to electricity. Common workshop/garage compressors are 110-120 Volt or 230-240 Volt. Compressor tank shapes are: “pancake”, “twin tank”, “horizontal”, and “vertical”. Depending on a size and purpose compressors can be stationary or portable.
