Compressed air glossary

A compressor that combines the machine, receiver, dryer and filtration on one frame. At AIRSTAHL, this is the K Series.

See also : K Series — 4-in-1 compressors

A heat exchanger that cools air at the compressor outlet. Much of the water condenses at this point and can be drained.

A filter that protects the compressor from dust in the intake air. In a dusty room it must be checked more often.

See also : Service kits

Loss of compressed air through a faulty fitting, hose or tool. Leaks make the compressor run for nothing and weigh heavily on the electricity bill.

See also : Cost of compressed air leaks · Compressed air leaks - how to detect and repair them

The piping that distributes air from the compressor to workstations. A ring main spreads pressure better than a single line.

See also : Connecting your compressor to the workshop air network · Connection

A standard that classifies compressed air quality by three criteria: particles, water and oil. A class is written as three digits; the smaller they are, the purer the air.

A tank that stores compressed air. It absorbs demand peaks, limits compressor starts and helps cool the air and separate water.

See also : Air receiver size · Air receivers

A component of an oil-injected screw compressor that separates oil from the compressed air before it leaves the machine. It is replaced during services.

See also : When should you service a screw compressor? · Service kits

A device that discharges condensate from the receiver, filters or dryer without manual action. It prevents forgotten draining and limits air losses.

See also : Connection

A unit of pressure. On a compressor, pressure is almost always given in gauge bar (above atmospheric pressure): 8 bar gauge is about 9 bar absolute.

See also : Bar and pressure - how to calculate the pressure you need · Flow, pressure and power converter

Cubic feet per minute, an imperial flow unit. 1 cfm is about 28.3 l/min.

See also : Flow, pressure and power converter

A valve that lets air flow in one direction only, for example to stop air from the receiver flowing back to the compressor when it stops.

A filter that captures fine droplets of oil and water in compressed air. It is installed ahead of sensitive points of use such as painting.

See also : Connection

Ambient air whose pressure has been raised by a compressor. It is used as an energy source to drive tools, machines and processes.

Oil formulated for compressors, different from engine oil. The type and viscosity depend on the technology (piston or screw) and are given in the manual.

See also : Which oil for a piston or screw compressor?

Water, often mixed with a little oil, that forms when compressed air cools. It must be drained regularly and treated before disposal.

A dryer that passes air over a moisture-absorbing material. It produces very dry air, needed when the network is exposed to frost or for demanding processes.

See also : Which air dryer should you choose for your compressor? · Air dryers

The share of time a compressor can run loaded. A piston compressor needs breaks; a screw compressor can run continuously.

See also : Piston compressor vs screw compressor - what really sets them apart

The amount of air produced or used per unit of time, in l/min, m³/min, m³/h or cfm. The compressor's flow must cover the consumption of all tools used at the same time.

See also : Which compressor for your workshop? · Flow, pressure and power converter

The air flow actually delivered by the compressor, referred to intake conditions. This is the figure to compare between machines, not the displacement, which always looks better.

See also : Flow, pressure and power converter

A counter that totals the compressor's running hours. Screw compressor services are scheduled from this meter.

See also : When should you service a screw compressor?

The phase where a screw compressor runs without producing air, between loaded phases. It still draws part of its power, hence the value of a compressor matched to demand.

See also : Compressor electricity cost

An operating mode where the compressor alternates between producing air (load) and idling (unload) according to network pressure.

The noise emitted by the compressor, measured in A-weighted decibels. A difference of 3 dB(A) means the sound energy doubles.

See also : Quiet compressor for workshops

A compressor whose compression chamber works without oil. It is chosen when the air must contain no trace of oil, for example in food or pharmaceutical production.

See also : Which oil for a piston or screw compressor?

A high-efficiency electric motor, often paired with a variable speed drive. It reduces the consumption of compressors that run a lot, such as the S 220 PM.

See also : S Series — screw compressors

A compressor that compresses air through the reciprocating motion of one or more pistons. Simple and robust, it suits intermittent use with rest periods.

See also : E Series — tank-mounted piston compressors · Piston compressor vs screw compressor - what really sets them apart

The temperature at which moisture in compressed air starts to condense. The lower it is, the drier the air: around +3 °C with a refrigerated dryer, much lower with a desiccant dryer.

See also : Which air dryer should you choose for your compressor?

The loss of pressure between the compressor and the point of use, caused by pipes, fittings, filters and the dryer. A well-sized network keeps it to a few tenths of a bar.

See also : Connecting your compressor to the workshop air network

A regulatory category that includes compressed-air receivers. Depending on their volume and pressure, they are subject to periodic inspections and requalifications.

See also : Maintenance and inspections

An instrument that displays pressure on the receiver, the compressor or at the point of use.

See also : Pressure gauges and accessories

A switch that stops the compressor when maximum pressure is reached and restarts it when pressure falls to the set threshold.

See also : Spare parts

A coupling for connecting and disconnecting a tool without tools. Several profiles exist: they must be the same throughout the workshop.

See also : Connection

A dryer that cools compressed air to condense its moisture, then drains it. It is the standard solution for tools and painting.

See also : Which air dryer should you choose for your compressor? · Air dryers

A device that opens automatically if pressure exceeds the permitted limit. It protects the receiver and the installation and must never be blocked or tampered with.

See also : Spare parts

A rotary compressor that compresses air between two helical rotors. It is designed to run for long periods, even continuously, with a steady flow.

See also : S Series — screw compressors · Piston compressor vs screw compressor - what really sets them apart

The electrical power needed to produce 1 m³/min of air at a given pressure. The lower it is, the more efficient the compressor.

See also : Cost of compressed air leaks

A starting method for three-phase motors that limits inrush current when the compressor starts.

A piston compressor that compresses air in two steps, with cooling in between. It reaches higher pressures more efficiently.

Electronics that match motor speed to actual air demand. It reduces idling and consumption when demand varies a lot.

The pressure at which tools and machines must be supplied, usually 6 to 7 bar for tools. The compressor is set slightly higher to make up for network losses.

See also : Bar and pressure - how to calculate the pressure you need