Glossary of air compressor terms

Absolute Pressure
The total pressure measured relative to a perfect vacuum, combining atmospheric pressure and gauge pressure. It represents the true pressure of the compressed air.
Atlas Copco wiki article on bar absolute

Absolute Zero
The lowest theoretical temperature, at which molecular motion ceases, equal to -273.15°C or 0 Kelvin. It is the baseline for absolute temperature scales.
Atlas Copco Compressed Air Manual

Absorption
A process where moisture or contaminants are taken up into the volume of a solid or liquid material, such as a desiccant absorbing water vapor from compressed air.
Atlas Copco Absorption Drying explanation

Absorption Dryers
Dryers that remove moisture from compressed air by absorbing water vapor into a desiccant material, which must be regenerated periodically.
Atlas Copco Compressed Air Manual

Activated Carbon
A porous material used in filters to adsorb oil vapors, odors, and hydrocarbons from compressed air, enhancing air purity.
Atlas Copco Activated Carbon Filters

Active Power
The actual electrical power consumed by the compressor motor to perform work, measured in watts (W).
Atlas Copco Compressed Air Manual

Adsorption
The process where moisture or contaminants adhere to the surface of a solid material (adsorbent), commonly used in adsorption dryers.
Atlas Copco Adsorption Dryers

Adsorption Dryers
Dryers that remove moisture by adsorbing water vapor onto desiccant surfaces, providing very dry compressed air suitable for sensitive applications.
Atlas Copco Adsorption Drying Technology

Aftercooler
A heat exchanger that cools compressed air immediately after compression, reducing temperature and causing moisture to condense for removal.
Atlas Copco After Cooler Description

Air-borne Energy Recovery
Recovering heat energy generated during air compression for reuse, improving overall system energy efficiency.
Atlas Copco Energy Efficiency Solutions

Air Composition
The mixture of gases in atmospheric air, mainly nitrogen (~78%), oxygen (~21%), and trace gases.
Atlas Copco Compressed Air Basics

Air Compressor
The primary device in a compressed air system that takes in ambient air and increases its pressure by mechanically reducing its volume or accelerating air velocity.
Basic Theory

Air Consumption
The volume of compressed air used by equipment or processes, typically measured in cubic feet per minute (cfm) or liters per second (l/s).
Air compressor measurements

Air Cooled Compressor
A compressor cooled by ambient air rather than water, using fans or fins to dissipate heat generated during compression.
Water cooled and air cooled air compressors

Air Dryer
Equipment that removes residual moisture from compressed air after cooling to prevent corrosion and damage in pneumatic systems; includes refrigerated and adsorption types.
Compressed air dryers

Air Receiver
A storage tank for compressed air that balances supply and demand, smooths pressure fluctuations, and helps remove moisture.
Atlas Copco Air Receiver description

Air Requirement
The specific volume and pressure of compressed air needed for a particular application or process.
Atlas Copco Air Receiver wiki

Air Treatment
Processes and equipment such as filters, dryers, and separators used to clean, dry, and condition compressed air.
Guide on compressed air treatment

Alternating Current (AC)
An electric current that periodically reverses direction, commonly used to power compressor motors. 

[General scientific reference]

Apparent Power
The product of voltage and current in an AC circuit, measured in volt-amperes (VA), combining both active and reactive power.

[General scientific reference]

Atmospheric Pressure
The pressure exerted by the earth’s atmosphere at sea level, approximately 101.3 kPa or 1 bar.
Atlas Copco Compressed Air Basics

Atomic Number
The number of protons in an atom’s nucleus, defining the chemical element.

[General scientific reference]

Axial Compressors
Dynamic compressors where air flows parallel to the axis of rotation through multiple stages of rotating and stationary blades, used for high flow rates.
Atlas Copco Compressed Air Manual

Booster Compressors
Compressors used to increase the pressure of already compressed air, often installed downstream to achieve higher pressures.
Atlas Copco Wiki on Booster Compressors

Boyle’s Law
A gas law stating that at constant temperature, the volume of a gas is inversely proportional to its pressure (P1V1 = P2V2).
[General scientific reference]

Bypass Regulation
A compressor control method where excess air is diverted around the compressor or system to regulate pressure without stopping the compressor.
Atlas Copco Regulation Systems

Cables
Insulated electrical conductors used to supply power to compressors and related equipment safely.
Atlas Copco Electrical Systems

Capacitive Measurement System
A sensor technology that detects moisture or other properties in compressed air by measuring changes in capacitance.
Atlas Copco Air Treatment Sensors

Carbon Filter
A filter containing activated carbon to remove oil vapors and hydrocarbons from compressed air.
Atlas Copco Air Treatment Filters

Celsius Scale
A temperature scale where water freezes at 0°C and boils at 100°C under atmospheric pressure.
[General scientific reference]

Central Control
A system managing multiple compressors and air treatment units from one location to optimize performance and energy use.
Atlas Copco Compressor Controls

Centralized Installation
A compressed air system design where compressors and treatment equipment are located centrally to supply multiple points.
Atlas Copco System Solutions

Centrifugal Compressors
Dynamic compressors that increase air pressure by accelerating air with impellers and converting velocity to pressure in a diffuser.
Atlas Copco Centrifugal Compressors Catalogue

Changes in State
Transitions between physical states of air or moisture, such as condensation or evaporation.
Atlas Copco Compressed Air Manual

Charles’ Law
A gas law stating that at constant pressure, the volume of a gas is directly proportional to its absolute temperature.
[General scientific reference]

Circuit-Breaker
An electrical safety device that interrupts power to prevent damage from overloads or short circuits.
Atlas Copco Electrical Safety

Clearance Volume
The small space remaining in a compressor cylinder between the piston and cylinder head at the end of compression stroke.
Atlas Copco Compressor Manual

Closed Cooling System
A cooling system where coolant circulates in a closed loop, preventing contamination and conserving water.
Atlas Copco Cooling Solutions

Compressed Air Central
A facility or system hub where compressed air is generated, treated, stored, and distributed.
Atlas Copco System Solutions

Compressed Air Distribution
The network of pipes and fittings delivering compressed air from the source to points of use.
Atlas Copco Distribution Systems

Compressed Air Quality
The level of purity of compressed air, including moisture, oil, and particle content, often defined by ISO standards.
Atlas Copco Air Quality Standards

Compressed Air Quality
The measure of compressed air purity, defined by content of moisture, oil, particles, and other contaminants, often specified by ISO standards.
Atlas Copco Air Quality Standards

Compressed Air Storage

Includes primary air receivers and secondary storage that help stabilize system pressure and supply during varying demand

Compressed Air System
An integrated arrangement comprising air compressors, air treatment units (filters, dryers), air storage receivers, and distribution piping designed to supply clean, dry compressed air at required pressures to industrial processes.

Compression in Several Stages
A process of compressing air in multiple steps with cooling between each stage to improve efficiency and reduce air temperature.
Atlas Copco Compressor Manual

Compressor Calculation
The process of determining appropriate compressor size, capacity, and power needs based on air consumption and application requirements.
Atlas Copco Sizing Guide

Compressor Central
Another term for compressed air central; the main installation where compressors and air treatment units are located.
Atlas Copco System Solutions

Compressor Package
A complete unit that includes the compressor, motor, controls, cooling system, and sometimes air treatment components ready for installation.
Atlas Copco Compressor Packages

Conductivity
A property indicating a material’s ability to conduct heat or electricity; relevant in heat exchangers used in compressed air cooling.
Atlas Copco Cooling Systems

Contactor
An electrically operated switch used to control compressor motor power remotely, enabling reliable start/stop operation.
Atlas Copco Electrical Controls

Continuous Capacity Regulation
A capacity control method that varies compressor output smoothly and continuously to match air demand without cycling.
Atlas Copco Variable Speed Drives (VSD)

Control and Monitoring
Systems that supervise and manage compressor performance, ensuring efficient operation, fault detection, and data collection.
Atlas Copco Control Systems

Convection
Heat transfer by the movement of air or liquid, used in air- or water-cooled compressors to remove compression heat.
Atlas Copco Thermal Management

Cooling Methods
Techniques for removing heat from compressors or compressed air, including air cooling, water cooling, and oil cooling.
Atlas Copco Cooling Solutions

Cost Allocation
The accounting process of attributing compressed air system costs to different plant departments or processes based on usage.
Atlas Copco Energy Efficiency Resources

Critical Pressure Ratio
The pressure ratio at which gas flow through an orifice or valve reaches sonic velocity, limiting maximum flow rate.
General reference: Atlas Copco Manual

Data Monitoring
The continuous collection and analysis of operating parameters such as pressure, temperature, flow, and energy consumption to optimize compressor system performance and maintenance.
Atlas Copco Control and Monitoring

Decentralized Installations
A compressed air system approach where compressors are located close to the point of use instead of a central compressor room, reducing distribution losses.
Atlas Copco System Solutions

Decibel (dB)
A logarithmic scale unit used to measure the intensity of sound such as compressor noise emissions.
Atlas Copco Noise Control Solutions

Degree of Recovery
The proportion of heat energy recovered from the compressor during operation, which can be reused for heating or other purposes, improving energy efficiency.
Atlas Copco Heat Recovery

Delta Connection
An electrical wiring method connecting three motor windings in a triangle circuit to supply three-phase power to compressor motors.
Atlas Copco Wiki on Electrical Connections

Dew Point
The temperature at which moisture in compressed air condenses into liquid, used as a measure of air dryness. Lower dew points indicate drier air.
Atlas Copco Air Dryers

Diaphragm Compressors
Positive displacement compressors using a flexible diaphragm to compress air without oil contact, ensuring oil-free air output for high-purity needs.
Atlas Copco Oil-Free Compressors

Diaphragm Filter
A specialized filter design using a flexible membrane for separating contaminants from compressed air, often in sensitive applications.
Atlas Copco Filtration Solutions

Dimensioning
The process of sizing compressors, piping, and accessories correctly to meet the calculated air demand and pressure requirements.
Atlas Copco Installation Best Practices

Direct Start
A method where a compressor motor is started by applying full voltage directly, typically used for small motors with low starting current.
Atlas Copco Control Systems

Displacement Compressors
Compressors that increase air pressure by mechanically reducing air volume in a cylinder or chamber, such as piston or rotary screw compressors.
Atlas Copco Compressor Types

Distribution System
The network of pipes, valves, and fittings that deliver compressed air from the compressor or air receiver to consumption points within an industrial facility

Double Acting Compressors
Piston compressors where air is compressed on both sides of the piston during two strokes, effectively doubling capacity.
Atlas Copco Compressed Air Manual

Drawing Symbols
Standardized graphical symbols used in compressor system diagrams to represent components like valves, filters, and compressors.
Atlas Copco Compressed Air Manual

Drying
The process of removing moisture from compressed air to prevent corrosion, freezing, and equipment damage downstream.
Atlas Copco Dryers

Dynamic Compressors
Compressors that boost air pressure by imparting velocity through rotating components like impellers; includes centrifugal and axial types.
Atlas Copco Centrifugal Compressors

Electric Motor
A device that converts electrical energy into mechanical energy to drive compressors. Most industrial compressors use three-phase motors.
Atlas Copco Wiki on Electrical Connections

Electrical Current
Flow of electric charge, measured in amperes (A), that powers the compressor motor.
Atlas Copco Wiki on Electricity

Electrical Voltage
The electrical potential difference measured in volts (V) that drives current through compressor motors and controls.
Atlas Copco Wiki on Electricity

Electricity
The flow of electrical energy used to power compressors and related control systems.
Atlas Copco Wiki on Electricity

Electromotive Force (emf)
The voltage generated by an electric source or motor acting as a generator, influencing compressor electrical performance.
Atlas Copco Wiki on Electricity

Electrons
Subatomic particles carrying negative charge, responsible for electrical current flow in compressor motors and circuits.

Energy Efficiency in Compressed Air Systems
Optimization practices involving system design, leak control, pressure management, and heat recovery to reduce energy consumption and operating costs.

Energy Recovery
Techniques to reclaim heat generated during air compression for beneficial reuse, such as space heating or process water heating, improving energy efficiency.
Atlas Copco Heat Recovery Solutions

Equivalent Pipe Length
The total length of piping including fittings and valves expressed as an equivalent length of straight pipe, used to calculate pressure losses accurately.
Atlas Copco Compressed Air System Design

Exhaust Emissions
Gaseous pollutants released from compressor engines (typically diesel or gas-powered) during operation.
Atlas Copco Compressed Air Manual

FAD (Free Air Delivery)
The volume of atmospheric air that a compressor delivers, usually measured at intake conditions (pressure, temperature). It’s a standard metric for compressor capacity.
Atlas Copco Compressor Sizing Guide

Filter
A device that removes solid particles, oil, and other contaminants from compressed air to protect equipment and ensure product quality.
Atlas Copco Air Filters

Filter Efficiency
A measure of how effectively a filter removes contaminants from compressed air, usually expressed as a percentage.
Atlas Copco Filter Solutions

Flow Through Pipes
The movement of compressed air through piping systems, affected by pipe diameter, length, and configuration which influence pressure drop.
Atlas Copco Compressed Air Distribution

Frequency
The rate, measured in hertz (Hz), at which alternating current changes direction; critical for motor operation in compressors.
Atlas Copco Wiki on Electricity

Frequency Converter
A device (also known as a Variable Frequency Drive) that adjusts the speed of an electric motor to match air demand, improving energy efficiency.
Atlas Copco Energy Saving Technologies

Fuses
Protective devices designed to interrupt electrical circuits in case of overcurrent, preventing damage to compressors and control systems.

Gas Constant
A physical constant used in gas equations, representing the proportionality factor in the ideal gas law (R = 8.314 J/mol·K).
[General scientific reference]

Gas Laws
Mathematical relationships describing the behavior of gases under varying temperature, pressure, and volume, essential for compressor design and operation.
Atlas Copco Compressed Air Manual

Gradual Start
An electrical motor starting method that ramps up voltage or frequency smoothly to reduce mechanical and electrical stresses.
Atlas Copco Control Solutions

Heat Exchanger
A device that transfers heat from compressed air or compressor components to cooling media like air or water, maintaining optimal temperatures.
Atlas Copco Wiki on Heat Transfer

Heat Transfer
The movement of thermal energy from compressor discharge air or surfaces to cooling systems through conduction, convection, or radiation.
Atlas Copco Wiki on Thermal Management

High Pressure Compressor
Compressors designed to generate pressures significantly higher than standard industrial levels, used in applications like gas injection or scuba filling.
Atlas Copco High Pressure Compressors

High Voltage
Electrical supply voltage above standard industrial levels (typically >1,000 V), often employed in large compressors requiring high power motors.
Atlas Copco Wiki on Electricity

Idling Time
The period during which a compressor runs without delivering compressed air to the system, leading to unnecessary energy consumption.
Atlas Copco Compressed Air Manual

Impedance
The total opposition a compressor motor’s electrical circuit presents to the flow of alternating current, combining resistance and reactance.
[General scientific reference]

Individual Gas Constant
The gas constant adjusted for a specific gas species, used in thermodynamic calculations involving compressed air.
[General scientific reference]

Inlet Regulation
A compressor control method where the volume of air entering the compressor is adjusted to match demand, improving efficiency.
Atlas Copco Control Systems

Installation’s Overall Economy
A comprehensive measure of a compressed air system’s cost-effectiveness, factoring initial investment, energy use, maintenance, and downtime.
Atlas Copco Lifecycle Costing

Insulation Class
A rating that defines the maximum temperature electrical motor winding insulation can withstand to ensure longevity and reliable operation.
Atlas Copco Wiki or Electric Motors

Intake Air
Ambient air drawn into the compressor for compression, whose temperature, humidity, and quality influence compressor efficiency and output air quality.
Atlas Copco Compressed Air Manual

Intake Air Filter
A filter that prevents dust and other airborne contaminants from entering the compressor, protecting internal components and maintaining efficiency.

Intake Pressure Variation
Fluctuations in the pressure of air entering a compressor, which can affect performance and efficiency.
Atlas Copco System Monitoring

Isentropic Process
An idealized thermodynamic compression with no heat loss or gain, often used as a reference for compressor efficiency.
Atlas Copco Wiki on Changes in States for Gases

ISO
International Organization for Standardization; sets standards including those for compressed air quality (ISO 8573 series).
Atlas Copco Air Quality Standards

Isobaric Process
A process in which pressure remains constant while other properties such as temperature or volume change.
Atlas Copco Wiki on Changes in States for Gases

Isochoric Process
A process at constant volume, where pressure changes due to temperature variations in the compressed air system.
Atlas Copco Wiki on Changes in States for Gases

Isothermal Process
A process where temperature remains constant during compression, typically an ideal scenario improving compressor efficiency.
Atlas Copco Wiki on Changes in States for Gases

Joule-Thomson Effect
A thermodynamic phenomenon where a gas cools or heats when allowed to expand at constant enthalpy through a valve or porous plug. In compressed air systems, this effect influences the temperature of air during expansion.
Atlas Copco Wiki on Gas Flow and the Joule Thomson effect

Laminar Flow
A fluid flow regime characterized by smooth, orderly, parallel layers of air or gas, typically occurring at low velocities in compressed air piping. This flow reduces pressure losses.
Atlas Copco Compressed Air Manual

Leakage
The unwanted loss of compressed air through holes, fittings, valves, or damaged piping, resulting in energy waste and reduced system efficiency.
Atlas Copco Article on Leakage

Life Cycle Cost (LCC)
The total cost of owning and operating a compressed air system over its full lifespan, including initial investment, energy, maintenance, and downtime.
Atlas Copco Wiki on Lifecycle Cost

Liquid Injected Screw Compressors
Screw compressors that inject liquid (usually oil or water) into the compression chamber to cool and lubricate the process, improving performance and reducing vibration.
Atlas Copco Water Injected Compressors

Loading
The condition when a compressor is actively compressing and delivering air, as opposed to being unloaded or in idle.
Atlas Copco Wiki on Load/Unload/Stop Control Systems

Logarithmic Mean Temperature Difference (LMTD)
An average temperature difference used in heat exchanger calculations to determine heat transfer efficiency when the temperature varies along the exchanger length.
Atlas Copco Wiki on Heat Transfer

Low Voltage
Electrical supply voltage classified as lower than industrial high voltage, usually under 1,000 volts, commonly powering smaller compressors.

Main Voltage
The primary electrical supply voltage provided to the compressor motor, essential for its operation. Typically varies depending on regional standards.
Atlas Copco Wiki on Electricity

Maintenance Costs
Expenses incurred in servicing, repairing, and keeping compressed air systems operational, including parts, labor, and downtime.
Atlas Copco Maintenance Services

Maintenance Planning
The strategy and scheduling of maintenance activities to optimize system reliability and minimize downtime and costs.
Atlas Copco Maintenance Planning

MD Dryer
Short for “Membrane Dryer,” a drying device that removes moisture from compressed air using selective permeable membranes—ideal for compact, point-of-use drying.
Atlas Copco Membrane Dryers

Medical Air
Compressed air that complies with strict purity standards for use in medical applications such as hospitals and dental clinics. Must be oil-free and low in contaminants.
Atlas Copco Medical Air Solutions

Membrane Dryers
Dryers that remove water vapor from compressed air through selectively permeable membranes, producing dry air without using regenerable desiccants.
Atlas Copco Membrane Dryers

Metal Resistor
A type of resistor composed of metal film or wire used in compressor electrical circuits for controlling current and voltage.
[General electrical reference]

Micro-organisms
Bacteria, fungi, and other tiny organisms potentially contaminating compressed air systems if moisture and oil are present—mitigated through proper filtration and drying.
Atlas Copco Article on Microorganisms in compressed air

Mobile Compressors
Portable compressors mounted on wheels or trailers, designed for temporary or remote applications such as construction sites.
Atlas Copco Portable Compressors

Modulation
A compressor control technique that adjusts the compressor output by modulating valve positions or motor speed to meet variable air demand.
Atlas Copco Compressor Controls

Moist Air
Compressed air containing water vapor or droplets; must be treated to prevent system corrosion and product contamination.
Atlas Copco Dryers and Air Treatment

Moisture Drain Traps
Automatic or manual valves installed to periodically discharge accumulated condensed water from compressed air systems to avoid contamination.

Molecular Movement
The random motion of molecules in gases like air; fundamental to understanding gas properties and compression processes.
[General scientific reference]

Molecules
The smallest particles of a substance that retain its chemical properties; compressed air primarily consists of nitrogen and oxygen molecules.
[General scientific reference]

Monitoring
Ongoing supervision of compressor system parameters, such as pressure, temperature, and power usage, to maintain performance and detect faults promptly.
Atlas Copco Control and Monitoring

Multi-stage Offloading
A compressor unloading method distributing air flow reduction over multiple stages to optimize energy use during partial load conditions.
Atlas Copco Compressor Control

Neutrons
Neutral subatomic particles found in an atom’s nucleus, contributing to its mass but carrying no electric charge, fundamental to atomic structure.
[General scientific reference]

Noise
Unwanted sound produced by compressors and associated equipment; reducing noise levels is important for workplace safety and compliance.
Atlas Copco Noise Control

Non-Sinusoidal Waveforms
Electrical current or voltage wave shapes that deviate from the ideal sine wave, potentially causing distortion and increased losses in compressor motors.
[General scientific reference]

Normal Litre
A unit of volume for gases measured at standard temperature and pressure (0°C and 1 atm), used to standardize air consumption measurement.
[General scientific reference]

Nozzle
A shaped device that controls the direction and speed of compressed air flow, often used in pneumatic tools and blow-off applications.
[General scientific reference]

Offloading/Loading
Compressor control modes where "loading" means the compressor is actively compressing air, and "offloading" is when it runs without compressing to save energy during low demand.
Atlas Copco Wiki on Load/Unload/Stop Control Systems

Ohm's Law
An electrical principle stating that current through a conductor is proportional to voltage and inversely proportional to resistance (I = V/R), fundamental to compressor motor design.
[General electrical reference]

Oil Filter
A filtration device used in oil-lubricated compressors to remove contaminants from the compressor oil, prolonging equipment life.
Atlas Copco Oil-Lubricated Compressors

Oil-Free Compressors
Compressors designed to produce compressed air without any oil contamination, often critical in food, pharmaceutical, and electronics industries.
Atlas Copco Oil-Free Compressors

Oil-Free Screw Compressors
Screw compressors that operate without oil in the compression chamber, ensuring the air remains oil-free for sensitive applications.
Atlas Copco Oil-Free Screw Compressors

Oil Temperature Control
Systems that monitor and regulate the temperature of lubrication oil in compressors to maintain optimal performance and prevent overheating.
Atlas Copco Compressor Cooling

Oil/Water Separation
The process and equipment used to separate oil from water in condensate collected from compressed air systems, important for environmental compliance.
Atlas Copco Blog Post on Oil Water Separation

Open Cooling System
A cooling method where external water is brought into direct contact with compressor components or cooling medium and then discharged.
Atlas Copco Compressed Air Manual

Operating Analysis
The evaluation of compressor operating data to optimize efficiency, reduce costs, and plan maintenance.
Atlas Copco SMARTLINK solution

Operating Costs
Expenses related to the running of compressed air equipment, including energy, maintenance, and consumables.
Atlas Copco Wiki on Lifecycle Cost

Optimised Compressor Operations
Strategies and controls designed to run compressors at peak efficiency, minimizing energy use and wear.
Atlas Copco Smart Air

Outlet Regulation
A control method that adjusts the compressor’s outlet airflow or pressure to match demand, helping prevent excess energy consumption.
Atlas Copco Compressor Controls

Over Compression
A condition where the compressor produces pressure beyond system requirements, leading to energy waste and potential equipment stress.
Atlas Copco Wiki on Overcompression

Overall Cost
The total expenses involved in selecting, purchasing, operating, and maintaining compressed air equipment over its usable life.
Atlas Copco Wiki on Lifecycle Cost

Overload Protection
Electrical and mechanical safeguards that prevent damage to compressor motors and components by limiting current or torque during abnormal operating conditions.
Atlas Copco Blog Post on Compressor Overload

Part Flow Measurement
A method to measure the flow rate of compressed air in part of the system, helping optimize performance and detect inefficiencies.
Atlas Copco Monitoring Solutions

Particle Filter
A filter designed to remove solid particles from compressed air to protect downstream equipment and improve air quality.
Atlas Copco Air Filtration

Phase Compensation
Electrical adjustment to correct phase differences between voltage and current in compressor motors, improving power factor and efficiency.
Atlas Copco Compressed Air Manual

Phase Displacement
Difference in phase angle between current and voltage in AC power systems, affecting compressor motor performance.
Atlas Copco Compressed Air Manual

Phase Voltage
The voltage measured across each winding in a three-phase electrical motor powering a compressor.

Pipe Resonance
Vibrations amplified in compressed air piping due to pressure pulsations or airflow dynamics, which can cause noise and fatigue.
Atlas Copco Compressed Air Distribution

Pipes
Tubing or conduits used to transport compressed air throughout a system; proper sizing and material affect efficiency and pressure losses.
Atlas Copco Distribution Systems

Piping Selection
Choosing appropriate materials and pipe sizes for compressed air distribution to minimize pressure drops and maintain system efficiency.

Piston Compressors
Positive displacement compressors that use reciprocating pistons within cylinders to compress air, suitable for high-pressure applications.
Atlas Copco Piston Compressors

Plasma
An ionized gas state sometimes used in specialized compressed air applications, such as advanced air purification or sterilization.
[General scientific reference]

Pneumatic Actuators
Devices that use compressed air to create controlled linear or rotary mechanical motion, commonly used to operate valves and automation equipment. They offer fast, reliable, and efficient actuation in industrial processes.
Atlas Copco Applications

Polytropic Process
A thermodynamic compression process where pressure and volume follow PVn=constantPVn=constant, where nn varies depending on heat transfer during compression.
Atlas Copco Compressed Air Manual

Positive Displacement Compressor
A type of compressor in which a fixed volume of air is trapped and mechanically compressed by reducing its volume, such as piston or rotary screw compressors.

Power
The rate of doing work, often referring to the electrical power consumed by the compressor motor, measured in watts (W) or kilowatts (kW).
Atlas Copco Wiki on Electrical Connections

Power Factor
The ratio of active power to apparent power in an AC electrical system, indicating efficiency of power usage by compressors.
Atlas Copco Compressed Air Manual

Prefilter
An initial filter stage that removes coarse particles before fine filtration in compressed air treatment systems, protecting downstream filters.
Atlas Copco Air Filters

Pressure
The force exerted by compressed air per unit area, expressed commonly in bar, psi, or pascal, critical for system design and operation.
Atlas Copco Compressed Air Basics

Pressure Intensifier
A device that increases compressed air pressure beyond the compressor’s maximum, used where very high pressures are required.
Atlas Copco Wiki on Boosters

Pressure Band
The allowable range of compressor discharge pressure within which the system is considered to be operating normally.
Atlas Copco Blog Post on Pressure Band

Pressure Dew Point
The temperature at which water vapor in compressed air condenses at the system's operating pressure, indicating moisture level in compressed air.
Atlas Copco Blog Post on Pressure Dew Point

Pressure Drop
Loss of pressure as compressed air flows through pipes, filters, valves, or other components due to friction or flow restrictions.
Atlas Copco Compressed Air Manual

Pressure/Flow Controller
Devices that regulate the pressure and flow of compressed air, maintaining constant system pressure and efficient air delivery.

Pressure Measurement
The process of gauging compressed air pressure using sensors or gauges to ensure correct system operation.
Atlas Copco Control and Monitoring

Pressure Ratio
The ratio of compressor discharge pressure to intake pressure, indicating how much the air is compressed.
Atlas Copco Compressor Specs

Pressure Relief
Safety devices or valves that release excess compressed air pressure to prevent system damage.
Atlas Copco Compressed Air Manual

Pressure Relief with Throttled Intake
A control method where intake air flow is reduced to lower compressor output and relieve excess pressure safely.
Atlas Copco Wiki on Compressor Regulation

Pressure Switch
An electrical switch activated by preset air pressure to control compressor operation or trigger alarms.
Atlas Copco Blog Post on Pressure Switch

Protection Classes
Ratings indicating the degree of protection electrical motors or devices have against dust, water, and mechanical impact, e.g., IP codes.

Protons
Positively charged subatomic particles in an atom's nucleus, determining the element's identity.
[General scientific reference]

Quality Class in Accordance with ISO
A classification system defined by ISO 8573 standards that specifies the allowed levels of contaminants (particles, water, oil) in compressed air for various applications.
Atlas Copco Air Quality Standards

Quantity of Ventilation Air
The volume of air supplied to ventilate a compressor room or installation to maintain safe operating temperatures and remove contaminants.
Atlas Copco Safety Guidelines

Radial Compressors
Also called centrifugal compressors, they increase air pressure by accelerating air radially through impellers and diffusers, suitable for high-volume, oil-free applications.
Atlas Copco Centrifugal Compressors

Radiation
Transfer of heat energy through electromagnetic waves, which can contribute minimally to cooling or heating in compressed air systems.
Atlas Copco Wiki on Heat Transfer

Reactance
The opposition to alternating current caused by inductance or capacitance in compressor electrical circuits, affecting motor power quality and efficiency.
[General scientific reference]

Reactive Power
The portion of power in AC circuits that oscillates between source and load, necessary for magnetizing compressor motors but not doing actual work.
[General scientific reference]

Recovery Potential
The capacity for reclaiming and reusing heat energy generated by compressors, leading to increased energy efficiency.
Atlas Copco Heat Recovery

Refrigerant Dryer
An air dryer that cools compressed air below its dew point using a refrigeration cycle to condense and remove moisture.
Atlas Copco Refrigerant Dryers

Regulation
The methods and systems used to control compressor output and maintain stable pressure within target parameters.
Atlas Copco Compressor Controls

Regulation System
Integrated control systems managing compressor load, pressure, and safety functions for optimal operation.
Atlas Copco Control Systems

Remote Monitoring
The ability to oversee compressor performance and conditions via networked digital interfaces or apps from distant locations.
Atlas Copco Smart Air & Remote Monitoring

Resistance
The opposition to electrical current flow in compressor motors and electrical circuits, causing power loss as heat.
[General scientific reference]

Resistance Thermometer
A temperature sensor that measures temperature based on the resistance change of a metallic element; used to monitor compressor temperatures.
Atlas Copco Monitoring

Resistive Measurement System
Sensors that detect changes in electrical resistance to measure parameters like temperature or moisture in compressed air.
Atlas Copco Wiki on Data Monitoring

Reverberation
The persistence of sound reflections in compressor rooms, contributing to noise levels and requiring acoustic treatments.
Atlas Copco Noise Control

Reynolds’ Number
A dimensionless quantity representing the ratio of inertial forces to viscous forces in fluid flow, used to characterize laminar or turbulent airflow in compressed air piping.
Atlas Copco Compressed Air Distribution

Ring Piping
A piping configuration forming a closed loop to supply compressed air evenly and reduce pressure drops in distribution systems.
Atlas Copco Compressed Air Systems

Room Constant
A value describing the acoustic absorption characteristic of a room, useful for designing compressor rooms to control noise.
Atlas Copco Acoustic Solutions

Roots Blowers
Positive displacement rotary lobe compressors that move large volumes of air at low pressure increases, often used in industrial aeration or vacuum systems.
Atlas Copco Wiki on Roots Blowers

Saving Possibilities
Opportunities for energy and cost savings in compressed air systems through efficiency improvements, controls, and leak reduction.
Atlas Copco Energy Savings

Screw Compressors
Rotary positive displacement compressors where two meshing screws compress air efficiently, popular for continuous industrial use.
Atlas Copco Screw Compressors

Scroll Compressors
Compressors using two interleaved spiral scrolls to compress air quietly and efficiently, often in small industrial and HVAC applications.
Atlas Copco Wiki on Scroll Compressors

Separation Efficiency
A metric describing how effectively filters or separators remove contaminants like oil and water from compressed air.
Atlas Copco Air Treatment Filters

Sequence Control
A control method that manages operation timing of multiple compressors in a system to optimize efficiency and reliability.
Atlas Copco Compressor Controls

Short-circuit Protection
Electrical protection that interrupts power in case of a short circuit to prevent damage to compressors and electrical systems.
Atlas Copco Compressed Air Manual

Single Acting Compressor
A piston compressor where air is compressed on only one side of the piston during each stroke.
Atlas Copco Compressed Air Manual

SI-System
The International System of Units used for scientific and engineering measurements including pressure (Pa), temperature (K), and flow (m³/s).
Atlas Copco wiki on SI system

Sound
Vibrations transmitted through air or solids, perceived by human ears; managing sound is important for compressor installation and operation.
Atlas Copco Noise Solutions

Sound Absorption
Materials or treatments applied in compressor rooms to reduce reflected sound and overall noise levels.
Atlas Copco Acoustic Solutions

Sound Dampening
Techniques and materials used to reduce noise levels emitted by compressors and air systems.
Atlas Copco Noise Control

Sound Measurements
Quantitative assessment of noise levels from compressors using decibel meters for compliance and safety.
Atlas Copco Noise Monitoring

Sound Power Level
A measure of the total acoustic energy emitted by a compressor or component, useful for noise assessment.
Atlas Copco Acoustic Documentation

Sound Pressure Level
The sound intensity experienced at a specific location, relevant to workplace noise exposure.
Atlas Copco Noise Control

Speed Regulation
Controlling compressor motor speed to match air demand, enhancing energy efficiency through variable frequency drives or other methods.
Atlas Copco Wiki on Speed Control

Standards
Technical and safety guidelines such as ISO and IEC that define compressed air system design, quality, and operation.
Atlas Copco Quality & Standards

Star Connection
A method of wiring three motor windings where one end of each winding is connected to a common point, used for starting compressors on high voltage.
Atlas Copco Wiki on Electrical Installations

Star/Delta Start
A motor starting method that initially connects windings in star to reduce starting current, then switches to delta for full power operation.
Atlas Copco Wiki on Electrical Installations

Start Sequence Selector
A control feature that determines the order compressors start to optimize system efficiency and reduce electrical peaks.
Atlas Copco Control Systems

Start/Stop Regulation
A basic compressor control method turning the machine on or off to match air demand, commonly used in fixed speed compressors.
Atlas Copco Compressor Controls

Starter
An electrical device used to start and stop compressor motors safely, often including protection features.
Atlas Copco Wiki on Electrical Installations

Sterile Filters
Highly efficient filters designed to remove microorganisms and contaminants to produce sterile compressed air for medical or pharmaceutical use.
Atlas Copco Blog on Sterile Filtration

Stroke Volume
The volume displaced by the piston in a single stroke of a reciprocating compressor cylinder.
[General scientific reference]

Suction Valve Unloading
A compressor control technique reducing intake air flow to unload the compressor, decreasing output without stopping the motor.
Atlas Copco Compressed Air Manual

Synchronous Speed
The speed at which the magnetic field rotates in an AC motor, determining compressor motor speed.
[General scientific reference]

Tables
Data charts or reference tables used in compressor technology to provide essential information such as pressure-temperature relationships, flow rates, and performance characteristics.
Atlas Copco Technical Documentation

Temperature
A measure of the thermal state of compressed air or equipment, typically expressed in degrees Celsius (°C) or Fahrenheit (°F), critical for compressor operation and air quality.
Atlas Copco Compressor Basics

Temperature Measurement
Techniques and sensors (like thermistors or resistance thermometers) used to accurately monitor compressed air or compressor component temperatures.
Atlas Copco Monitoring Solutions

Thermal Capacity
The ability of a material or system part to absorb and store heat, important in compressor cooling system design.
Atlas Copco Cooling Solutions

Thermal Conductivity Number
A property of materials indicating their efficiency in conducting heat, used for selecting heat exchangers and insulating materials in compressed air systems.
Atlas Copco Cooling Systems

Thermistor
A temperature-sensitive resistor widely used as a temperature sensor in compressor systems to monitor temperature accurately.
Atlas Copco Sensors and Monitoring

Thermodynamics
The branch of physics dealing with heat, work, and energy transfer; key principles underpin compressor design and operation.
Atlas Copco Compressed Air Manual

Three Phase System
An electrical power system with three alternating currents phased evenly apart, commonly supplying industrial compressors for efficient operation.
Atlas Copco Electrical Systems

Throttling
The intentional restriction of air flow by partially closing a valve to control pressure or flow in compressed air systems.
Atlas Copco Compressor Control

Throttling the Inlet
A method to reduce compressor load by restricting the air intake to lower output pressure or capacity.
Atlas Copco Controls

Tooth Compressor
A type of positive displacement compressor using intermeshing rotors with teeth that trap and compress air; also known as lobe compressors.
Atlas Copco Types of Compressors

Torque
The twisting force applied by the motor to rotate the compressor shaft, critical for compressor startup and operation.
Atlas Copco Electrical and Mechanical Systems

Turbo Compressor
A dynamic compressor using high-speed impellers to compress air, typically used for large volume applications with oil-free air requirements.
Atlas Copco Centrifugal Compressors

Turbulent Flow
A flow pattern in compressed air piping characterized by chaotic and irregular fluid movement, increasing pressure drop and energy losses.
Atlas Copco Compressed Air Distribution

Twin Screw Compressors
Compressors using two interlocking helically grooved rotors to trap and compress air smoothly and efficiently.
Atlas Copco Screw Compressors

Types of Compressors
Various compressor technologies categorized mainly as positive displacement (piston, screw) or dynamic (centrifugal, axial) types for different applications.
Atlas Copco Types of Compressors Overview

Vacuum Pumps
Devices that remove air from a closed system to create a vacuum for processes requiring reduced pressure.
Atlas Copco Vacuum Solutions

Valve Off-loading
A control strategy where compressor valves are partially opened to reduce compression load during low demand, saving energy.
Atlas Copco Compressor Controls

Vane Compressors
Rotary positive displacement compressors using a rotor with sliding vanes for compressing air; suitable for specific low-flow applications.
Atlas Copco Wiki on Vane Compressors

Vane Regulation
Adjusting the position or number of rotor vanes in vane compressors to control output air volume and pressure.
Atlas Copco Compressor Controls

Variable Discharge Port
A mechanical feature allowing control of airflow by varying the port size through which compressed air exits the compressor, regulating capacity.
Atlas Copco Compressed Air Manual

Ventilation Fan
A fan installed in compressor rooms to maintain air quality and temperature by supplying fresh air and removing heat and contaminants.
Atlas Copco Compressed Air Manual

Volume Rate of Flow
The volumetric measurement of air passing through a compressor or pipe per unit time (e.g., cubic feet or meters per minute).
[General scientific reference]

Water Content in Compressed Air
The amount of moisture present in compressed air, usually expressed in ppm or dew point temperature; controlling it is vital for equipment longevity and product quality.
Atlas Copco Air Dryers

Water Cooled Compressor
Compressors that use water as a cooling medium to remove heat generated during compression, beneficial in large or continuous operations.
Atlas Copco Wiki on Water Cooled Compressors

Water Separator
A device that removes condensed water droplets from compressed air to prevent corrosion and damage in downstream equipment.
Atlas Copco Condensate Management

Water Vapor
Moisture in the form of invisible gaseous water within compressed air, which can condense and cause problems if untreated.
Atlas Copco Air Dryers and Filtration

Water-borne Energy Recovery
The process of recovering heat energy from compressed air using water-based cooling circuits for reuse in heating and industrial processes.
Atlas Copco Wiki on Energy Recovery in Compressor Systems

Working Pressure
The typical or specified pressure at which a compressed air system or compressor operates during normal service.
Atlas Copco Wiki on Working Pressure