Definitions:
Absolute Pressure: The pressure regarding absolute Zero, is about an absolute Vacuum; it equals the sum of the Atmospheric Pressure and the Gauge Pressure. (BS 5791-1)
Absolute Temperature: The temperature measured from absolute zero.
After Cooling: The removal of heat from the air after compression is complete.
Ambient Temperature: The temperature of the environment in which the equipment.
Atmospheric Pressure: The Absolute Pressure of the atmosphere as measured at the place under consideration (BS 5791-1).
Compressor: A device that causes a gas to flow and produce Pressure; it converts mechanical force and motion into pneumatic fluid power.
Compressor Capacity: The actual volume rate of flow compressed and delivered at the standard discharge point, at stated inlet conditions, usually expressed in terms of Free Air Delivered. (FAD)
Compressor-Mobile: A compressor either trailer or vehicle mounted which is designed to be frequently moved from one operating site to another. A mobile compressor is always wheel-mounted.
Condensate: The liquid formed from water vapor in the air because of a drop in the air temperature and/or an increase in pressure.
Dew Point: The temperature at which air is fully saturated with water vapor at the pressure prevailing.
Displacement: The volume displaced by the compression element of the first stage per unit of time.
Dryer: A device that reduces the water vapor content of the compressed air.
Explosion Proof: (flameproof enclosure) apparatus placed in an enclosure that can withstand an internal explosion of an explosive mixture without igniting an explosive atmosphere surrounding the enclosure. (See BS 5501).
Filter: A device that removes foreign matter from the working medium.
Gauge Pressure: The pressure as measured concerning atmospheric pressure; where no other indication is given, pressures expressed in the “bar” are assumed to be gauge pressures (BS 5791-1).
Inter Cooling: The removal of heat from the air between stages in multi-stage compression.
Multi-Stage Compression: Compression from initial to final pressure in two or more stages (steps) with cooling between each.
Pressure Ratio (total): The ratio between the absolute discharge pressure and the absolute inlet pressure. (BS 5791-2)
Pressure:
“Design Pressure” (Maximum Allowable Pressure)-the pressure at which the pressure relief valve starts to lift.
“Maximum Working Pressure” – a pressure to which the vessel or system may be continuously exposed without detrimental effect on any component.
“Normal Working Pressure” – a pressure less than the maximum working pressure at which the system operates.
Pressure Regulator (Pressure Reducing Valve): A device that reduces the line pressure and maintains it relatively constant despite changes in inlet pressure and outlet flow rate.
Pressure Relief Valve (Safety Valve). A device that limits the maximum system pressure by exhausting the compressed air to the atmosphere when the required back pressure is exceeded, also known as a back pressure regulator.
Receiver, Air: A pressure vessel in which compressed air is stored.
Relative Humidity: The ratio of the amount of water vapor contained in a volume of air at a specific temperature and pressure, to the maximum amount possible under these conditions; normally expressed as a percentage.
Separator: A device that removes liquids from the compressed air.
Single-Stage Compression: Compression from initial to final pressure in a single stage (step)
Standard Reference Atmosphere: the agreed atmosphere to which specification valves and test results determined in other atmospheres are corrected (ISO 8778); pneumatic fluid power uses 1 bar (100kpa), 20°C and 65% RH (ISO 8778); the compressor and pneumatic tool industries also use 1 bar, 20°C anc°C and 65% RH (BS
5344); the aerospace (ISO 2533) and petroleum (BS 5579) industries both use.
Adsorption: The process by which a highly porous surface attracts and removes the moisture from compressed air. the desiccant is capable of being regenerated.
CFM (Cubic Feet per Minute). The standard measurement of airflow. The flow rate of air is measured and converted to a standard set of reference conditions.
Desiccant. A material having a large proportion of surface pores, capable of attracting and removing water vapor from the air.
Free Air Delivery (FAD). Actual quantity of air delivered at the conditions of temperature and pressure existing at the inlet to the compressor.
Full Load. Air compressor operation at full speed with a fully open inlet delivery of maximum airflow.
Intercooler: A device that removes the heat of compression of the air between consecutive stages of multi-stage compressors.
l/min (liters per minute): The standard measurement of airflow. The flow rate of air is measured and converted to a standard set of reference conditions.
M3/min (meter’/per minute): The standard measurement of airflow. The flow rate of air was measured and converted to the standard set of reference conditions.
Online/offline pressure: The minimum and maximum discharge pressures at which the compressor will switch from unload to load operation (online) or from load to unload (offline).
Pneumatic tools: Tools that operate by air pressure.
Bar G (bar gauge): The standard metric measurement of air pressure.
PSI (pounds per square Inch): The standard imperial measurement of air pressure.
Receiver: A vessel or tank used for storage of air under pressure.
Start and stop control: A system in which air supply is matched to demand by the starting and stopping of the unit.