Glossary of Compressed Air Terms :: F :: Glossary Index A B C D E F G H I J K L M N O P Q R S T U V W X Y Z FAD Free air delivery. Air at the atmospheric conditions of the site and unaffected by the compressor. Flow is measured at the discharge valve of the compressor, after the aftercooler, the water separator and built in check valve. Capacity and power consumption are corrected to ISO 1217 standard reference conditions: Ambient temperature = °20C, Ambient pressure = 1 bar(a), Relative humidity = 0%, Cooling water/air = 20°C, Effective working pressure at discharge valve = 7 bar(a). Fatigued A structural failure of the filter medium due to flexing caused by cyclic differential pressure. Ferrography An analytical method of assessing machine health by quantifying and examining ferrous wear particles suspended in the lubricant or hydraulic fluid. Fick's law of diffusion A law of chemistry and physics: the rate of diffusion of one substance in another is proportional to the negative gradient of the concentration of the first substance. Filter A device that removes solid contaminants, such as dirt or metal particles, from a liquid or gas (air is a gas), or that separates one liquid from another, or a liquid from a gas. The term filter describes the complete unit ... housing, filter element, internal by pass. Filter breather A filtering unit for vented enclosures installed to prevent dirt and foreign matter from entering the enclosure. Also prevents oil loss by retaining oil droplets and draining the oil back to the sump. Filter coalescing A filter unit that combines three principles to filter out oil aerosols: 1) Direct interception - A sieving action, 2) Inertial impaction - Collision with filter media fibers, 3) Diffusion -Particles travel in a spiral motion, presenting an effective frontal area thus capturing particles within the filter medium. Filter efficiency The ability of a filter to remove specified test contaminants under specified test conditions from a specific test fluid, air, gas or liquid. Expressed as a percentage of the quantity of test contaminant introduced into the inlet of the filter test system Filter element The porous device which perform the actual process of filtration. Filter head An end closure for the filter case or bowl that contains one or more ports. Filter housing Something that covers or protects the filter assembly.   Filter inline Inlet and outlet connections are located at the same level on opposite sides of the filter or other device installed on the pipeline. Filter life test A type of filter capacity test in which a clogging contaminant is added to the influent of a filter, under specified test conditions, to produce a given rise in pressure drop across the filter or until a specified reduction of flow is reached. Filter life may be expressed as test time required to reach terminal conditions at a specified contaminant addition rate. Filter medium The porous material contained inside the filter to (a) separate the contaminants from the incoming air, gas, or liquid. (b) separate the liquid from the gas. Filter medium is usually made of paper, wire mesh, special cellulose, or a combination. Filter oil bath A labyrinth type filter having the active surfaces continuously splashed with oil. Most pollutants are absorbed by the oil which when circulated releases its pollutants, which sink by gravity to the bottom of the oil pan. Filter separator Filtering unit that separates solids and liquid droplets from gas (air). Widely used in removing oil from a gas or air. Filtration The physical or mechanical process of separating insoluble particulate matter from a fluid, such as air or liquid, by passing the fluid through a filter medium that will not allow the particulate to pass through it. First law of thermodynamics The amount of work done on or by a system is equal to the amount of energy transferred to or from the system. Fixed compression ratio is the design (built-in) compression ratio for a rotary unit having this feature Flange A bolted rim used for attachment to another object. Flash point Is the lowest temperature to which oil must be heated under standardized test conditions to drive off sufficient inflammable vapour to flash when brought into contact with a flame. Flash points of petroleum based lubricants increase with increasing pressure. Flexible mounting Vibration isolation mount. Provides reductions in vibration transmission. Flow The volume of a substance passing a point per unit time (e.g., meters per second, gallons per hour, etc.). Flow control valve A valve that controls the flow of air that passes through the valve. Used often for retardation or timing circuits, but especially for regulating the piston speed in cylinders. Flow diagram A schematic flow sheet showing all controls involved with the system. Flow meter An instrument for measuring the amount of air flow of a compressor. Measured in CFM. Flow rate The rate (in liters or gallons per minute, cubic meters or cubic feet per second, or other quantity per time unit) Air related flows are usually expressed in CFM, SCFM, ACFM, ICFM Flushing A circulation process designed to remove contamination. Foot A device for mounting cylinders. Forced draft fan A fan that generates (by pushing) a flow of ambient air over the exterior of the finned pipes to dissipate the sensible heat. Fouling Accumulation of foreign matter, such as mud or debris, in a cooler, pipe, or valve. In a cooler, H 2 O D P and D T will be seen to increase, as well as CTD. Free air (FAD) Free air delivery. Air at the atmospheric conditions of the site and unaffected by the compressor. Flow is measured at the discharge valve of the compressor, after the aftercooler, the water separator and built in check valve. Capacity and power consumption are corrected to ISO 1217 standard reference conditions: Ambient temperature = °20C, Ambient pressure = 1 bar(a), Relative humidity = 0%, Cooling water/air = 20°C, Effective working pressure at discharge valve = 7 bar(a). Friction Surface resistance to relative motion, which slows down movement and causes heat. FRL Filter, Regulator and lubricator sometimes combined in one unit Frost point Is the unique temperature to which the air (or any gas) must be cooled in order that it shall be saturated with respect to ice. Full load Achieved when the air compressor is running at full RPM with a fully opened inlet and discharge, delivering the maximum volume at the rated pressure. Glossary Index A B C D E F G H I J K L M N O P Q R S T U V W X Y Z