What Is an Air Compressor Accumulator?

The primary purpose of an air accumulator is acting as an air reservoir. In the same way a water reservoir stores drinking water for future use, an air accumulator takes the air discharged from the compressor and stores it for use in tools or instrumentation. Many tools are used intermittently. If they are connected directly to an air compressor they will either lack sufficient air capacity to operate properly or the compressor will be starting and stopping frequently, resulting in premature compressor wear and failure. The accumulator provides a steady source of air capacity. Larger accumulators may have multiple compressors connected and permit connection to many pneumatic devices running at different capacities.

A critical function of an air accumulator is to regulate output pressure of the compressor. Reciprocating air compressors create a pulsing pressure output that can be difficult to use in some tools and can damage pneumatic instrumentation. The accumulator acts as a pressure control by absorbing the pressure pulses into the air stored in the accumulator. This results in a more constant pressure output for the devices connected to it.

Air contains water molecules that do not compress with the air leaving a compressor. Water can be discharged from the compressor and can damage tools or instrumentation. Many accumulators have a water drain at their low point that allows removal of free water to prevent it entering downstream equipment. Along with other filtration, the accumulator can help remove water from the compressed air system and provide a cleaner air source.

Multiple air accumulators can manage complex air systems and are much less expensive than multiple air compressors. A main accumulator on the compressor discharge provides primary capacity and pressure control for the system. If a downstream device has a high but intermittent load, a secondary accumulator provides storage capacity for that device without the need for an additional compressor.