January 22, 2013
Reciprocating Air Compressors are commonly known as piston driven compressors. They are generally smaller and portable, a popular style for contractors. Larger units are available for industrial use and are less expensive than rotary screw compressors, but keep in mind they are noisier and vibrate more.
How they work
The compression element in a reciprocating air compressor is a piston inside a cylinder driven by a crankshaft. They are positive displacement machines, this means they increase air pressure by reducing volume. The motor (electric or gas) powers the crankshaft to move the piston up and down. The compressed air is pushed into a high pressure holding tank. A one way check valve prevents the air from coming back into the cylinder. The air is now ready for use. Set the regulator to the amount of pressure you need for your particular application. Most power tools will have the PSI requirement stamped on the tool near the fitting for the air hose.
- Single-stage and two-stage reciprocating air compressors are available.
- Single-stage compressors are used for pressure requirements in the range of 70-100 psig.
- Two-stage compressors are used for higher pressures of 100-250 psig.
Reciprocating units are typically 1HP to 50HP. Models over 100 HP are usually the Rotary Screw or Centrifugal type.
Piston driven compressors can be powered by electricity, gas or diesel motors and are for intermittent use.
Small single-stage units are used in home workshops, mechanics garages and truck mounted for contractors in the field. Hand tools such as grinders, power nail guns and ratchets are examples of intermittent use. Air powered hand tools are much lighter than their electric or gas powered models. If you need a continuous flow of air such as spray painting, then a rotary screw compressor may be a better option.
Large industrial units can be found in manufacturing plants. A two-stage system can be installed with a filtering system. For clean dry air in facilities such as laundry and printing consider a refrigerated dryer to remove liquid and solid contaminants. A desiccant dryer will provide the purest, driest air for applications in robotics or pharmaceutical companies.
Advantages of a Reciprocating Air Compressor
- Less expensive than Rotary or Centrifugal
- Noisier than other types of models
- Vibration may be an issue
Proper valve maintenance is critical for maximum efficiency. Lubricated compressors if maintained regularly will last much longer than the oil less models. Make sure the oil you use is clean and pure. Check the reservoir and filters often.