FEATHER VALVE – A valve which consists of a strip of ribbon steel which covers a slightly narrower slot when the value is closed.

FINGER VALVES – Valves consist of narrow strips of stainless steel, fastened to the seat at one end and free to flex along their length. Suitable for light service.

FIXED COMPRESSOR – A compressor mounted upon a permanent base as concrete for service not requiring removal from place to place.

FREE AIR – Air at atmospheric condition at the point where a compressor is installed.

FREE AIR UNLOADER – An automatic device that varies the amount of air or gas being pumped.

FADE (brake) – A condition that occurs when there is little braking effect with full brake pedal force.

FIFTH WHEEL – is the swivelling type arrangement at the rear of a tractor unit. The fifth wheel carries the front part of the semitrailer.

FINAL DRIVE – The final gear reduction between the engine and the drive wheels.

FIXED CALIPER DISC BRAKES – Disc brakes using a calliper which is

fixed in position and cannot move.

FLOATING CALIPER DISC BRAKES – Disc brakes using a calliper mounted through rubber bushings which permit the calliper to float, or move, when the brakes are applied.

FLUID FLY WHEEL – A liquid coupling used to transmit the engine effort (torque) to a clutch and transmission. This coupling is always a major part of the engine flywheel.

FOOT PRINT – Area of road that is in contact with the tyre.

FORWARD CONTROL TRUCK – has the engine either in or below the driver’s cabin.

FORWARD EFFICIENCY – is the ratio of the amount of driver input torque which is available at the wheels to turn the same to the total amount of input torque from the driver at the steering wheel.

FOUR WHEEL DRIVE – Some cross country vehicles (Jeeps) have this arrangement. In this case, the engine power is transmitted to all the four wheels of the vehicle. The main advantage of this arrangement is the entire vehicle weight is available for traction.

FOUR WHEEL STEERING – Type of steering system in which all the four wheels of a vehicle are turned for steering.

FOUR SPEED TRANSMISSION – A transmission with four forward speeds or gear ratios.

FRAME – The assembly of metal structural parts and channel sections that forms the base and supports the engine and body and is supported by the vehicle wheels.

FRONT AXLE – In a vehicle, the front axle transmits the weight of the front part of the vehicle to the road surface through the front wheels. It also carries the mechanism for steering the vehicle. In the case of front wheel drive, it incorporates both steering and driving mechanisms.

FRONT END GEOMETRY – The angular relationship between the front wheels, wheel attaching parts, and vehicle frame. Includes camber, caster, king pin inclination, toe in and toe out on turns.

FULL FLOATING AXLE – An axle design usually used on heavy trucks where the vehicle weight is carried by bearings in the wheel hubs, or the drive wheels and the axles are used only to transfer driving torque.

FUEL FILTER – A kind of strainer in which there are openings of definite size all over the surface, which retains contaminants in the fuel and permits supply of dust free fuel to the fuel injection system.

FUEL LINE – Thick walled high pressure tubes connecting the delivery end of the fuel injection pump with an injector nozzle located in each of the cylinder head.

FUEL METERING – Measuring and delivering the required amount of fuel for each cycle in accordance with the engine load and delivering the same amount of fuel to each cylinder for each power stroke of the engine.

FUEL PUMP DELIVERY VALVE – assembly relieves the high pressure pipe and maintains a residual pressure in the high pressure pipe. It also reduces the work per cycle in pressurizing the fuel in the system.

FUEL TRANSFER PUMP – A mechanical device used to transfer fuel from the low level fuel tank to the injection pump.

FACING SAND – Specially prepared sand in the mould adjacent to the pattern to produce a smooth casting surface.

FALSE CHEEK – A cheek used in making a three part mould in a two part mould.

FALSE ODDSIDE – Permanent odd side made of plaster or other material.

FEED HEAD – A reservoir of molten metal provided to compensate for contraction of metal as it solidifies, by the feeding down of liquid metal to prevent voids. Also called a RISER.

FILLETS – Properly positioned fillets materially increase the strength and soundness of the castings. They reduce shrinkage cracks and erosion of sand at sharp intersections.

FIN – A thin piece of metal projecting from a casting at the parting line or at the junction of the cores or of cores and mould etc.

FLASH – Thin fin or web of metal extending from the casting along the joint line as a result of poor contact between cope and drag moulds.

FLASK – Container in which a mould is made.

FLOW OFF GATE – Channel cut from the mould to the riser.

FLUORESCENT CRACK DETECTION – Application of fluorescent liquid to a part, then removing the excess from the surface, which is then exposed to ultraviolet light. Cracks show up as fluorescent lines.

FACING SAND – Sand that forms the face of the mould which comes in contact with the molten metal.

FALKIRK SAND – Moulding sand with a coarse, open texture. It has very good permeability and moderate binding qualities.

FERRIC OXIDE – Red iron oxide, commonly available as haematite ore. Used in ground form in cores and moulds to increase hot compressive strength.

FERRITE – A solid solution of one or more elements in body centered cubic iron. Iron which contains little or no carbon. It is very soft and ductile and is known as alpha iron. A magnetic form of iron.

FERROALLOYS – Alloys containing of certain elements combined with iron, and used to increase the amount of such elements in ferrous metals and alloys. In some cases the ferroalloys may serve as deoxidizers.

FERROALUMINIUM – An alloy of iron and aluminium containing about 20% iron and 80% aluminium.

FERROCHROMIUM – An alloy of iron and chromium available in several grades containing from 60-72% chromium and from 0.06-7% carbon.

FERROMAGNETIC MATERIAL – A material that in general exhibits the phenomena of hysteresis and saturation, and whose permeability is dependent on the magnetizing force.

FERROMANGANESE – An alloy of iron and manganese containing from 78-82% manganese.

FERROMOLYBDENUM – An alloy of iron and molybdenum containing 58-64% molybdenum.

FERROPHOSPHOROUS – An alloy of iron and phosphorous containing 70% iron and 25% phosphorous.

FERROSILICON – An alloy of iron and silicon available in several grades containing different percentages of silicon from 14-20% silicon, 42-52% silicon, 69.5-82% silicon, 82-88% silicon and 88-95% silicon.

FERROUS – From the Latin word FERRUM meaning iron, describes an alloy containing a significant amount of iron.

FERROUS METALS – All metals that are alloys of iron, carbon, and other materials.

FIBRE GLASS – A resin matrix reinforced with glass fibres for strength. A reinforced plastic manufacturing material with many applications.

FILTER – In radiography a device, usually, a thin metallic layer inserted into a beam of radiation so as to modify the transmitted spectrum of radiation. It may be used to enhance or reduce contrast or minimize undesirable scattered radiation.

FIRE BRICK – Brick made of refractory clay or other material which resists high temperatures.

FIRE CLAY – A type of clay which is resistant to high temperatures.

FIXER (hypo) – A photographic processing solution, the principle function of which is to dissolve the undeveloped silver halide grains from the developed film, thus making the image more prominent. It often serves also to harden the gelatine and halt the developing process.

FLUX – A solid, liquid or gaseous material that is applied to solid or molten metal in order to clean and remove oxides.

FOAM RUBBER – It is also called sponge. Foam rubbers are formed by the inclusion of chemicals in rubber compounding which form gases during vulcanization.

FREE CARBON – The part of the total carbon in steel or cast iron that is present in the elemental form as graphite or temper carbon.

FREE FERRITE – Ferrite that is structurally separate and distinct as may be formed without the simultaneous formation of carbide when cooling hypo eutectoid austenite into the critical temperature range.

FILM LUBRICATION – Type of lubrication in which the two metallic surfaces are separated by a continuous film of liquid oil of measurable thickness which forces itself between them.

FIRE POINT OF OIL – The temperature at which the oil vapour on the oil surface ignites and burns for at least five seconds, when heated gradually, under specified test conditions.

FLASH POINT OF OIL – The temperature at which a momentary flash appears on the heated oil surface when a test flame is applied, under specified test conditions. It is a rough indication of the tendency of the oil to vaporize.

FOOT STEP BEARING – The bearing at the foot of a vertical shaft.

FORCE FEED LUBRICATION – A gear pump takes oil from the sump and delivers it to the distributor ducts which connect with all the main bearings and camshaft bearings, from where the oil reaches the various parts that need lubrication.

FORCE OF FRICTION – The least force acting parallel to the sliding surfaces of the bodies in contact, which will cause one body to slide over the other.

FRICTION – The force which acts between two bodies at their surface of contact so as to resist their sliding on each other, due to roughness of the surfaces. Also called FRICTIONAL FORCES.

FRICTION ANGLE – Angle which the resultant force makes with the normal to the plane when sliding begins. Also called LIMITING ANGLE OF RESISTANCE or LIMITING ANGLE OF REACTION.

FRICTION BEARINGS – Bearings having sliding contact between the moving surfaces. Sleeve bearings, such as those used in connecting rods, are friction bearings.

FLAME DETECTOR – A device that monitors the flame in a furnace that is burning oil, gas, or pulverized coal fuel. Failure of the flame results in a signal and the actuation of various protective controls on the fuel feed to prevent an explosion.

FLAME SAFEGUARD SYSTEM – An arrangement of flame detection system, interlocks and relays, which will sense the presence of a proper flame in a furnace and cause fuel to be shut off to the furnace if a hazardous (improper flame or combustion) condition develops.

FLASH POINT – It is the temperature at which the quantities of vapour which a combustible fuel emits into the atmosphere are sufficient to allow a spark to ignite the vapour air mixture above the fluid.

FLUE DUST – Solid particles (smaller than 100 microns) carried in the products of combustion.

FLUE GAS ANALYZER – Device which measures the percentages of volume of carbondioxide, carbon monoxide and oxygen in the flue gas of a boiler.

FLY ASH – Combustion ash so fine that is carried up and into the atmosphere by the movement of the flue gases. It can become neighbourhood nuisance by settling on surfaces in the area after it loses its velocity.

FOG – Suspended liquid particles formed by condensation of vapour.

FORCED DRAFT FAN – The fan that pushes or forces air into the furnace, usually at a pressure higher than atmospheric pressure.

FRACTIONAL DISTILLATION – A process of separation on the molecular basis or on the basis of the boiling point of various fractions.

FREE LIQUIDS – Liquids which readily separate from the solid portion of a waste under ambient temperature and pressure.

FUEL – The substance that is burned to produce heat and create motion in an engine or heat substances. Any combustible substance.

FUEL CALORIEMETER – A meter (also called oxygen bomb) to determine the heating value of 1 kg of fuel by burning a sample of the fuel under controlled conditions.

FUGITIVE DUST – Particulate matter composed of soil which is uncontaminated by pollutants resulting from industrial activity. Fugitive dust may include emissions from haul roads, wind erosion of exposed soil surfaces and soil storage piles, and other activities in which soil is either removed, stored, transported, and redistributed, also solid air borne particulate matter emitted from any source other than through a stack.

FUME – Any kind of noxious vapour arising from a process of combustion or chemical reactions. Includes smoke, odorous materials, metallic dust.

FUME AFTERBURNERS – Units designed to consume combustible fumes by means of a direct fired combustion chamber through which the fumes must pass on their way to the stack and the atmosphere.

FURNACE EXPLOSION – The ignition and almost instantaneous explosion of highly inflammable gas, vapour or dust accumulated in a boiler setting.

FLAME STABILIZATION – Making the flame to be more or less stable at a particular location in the combustion chamber by a system whereby part of the high temperature products of combustion can be caused to recirculate in order to ignite fresh reactants.

FLOW COEFFICIENT – Ratio of axial components of absolute velocity of fluid stream to the blade velocity at that location.

FLOW LOSSES – Pressure loss due to friction and turbulence. This consists of combustion chamber loss, heat exchanger loss (air side), heat exchanger loss (gas side), intercooler loss (air side) and duct losses occurring between components and at intake and exhaust.

FLUID ANGLES – Angles at which the fluid enters and leaves a blade. These are seldom the same as the blade angles.

FOIL NOZZLE – A nozzle formed by curved airfoil sections or facsimiles of airfoils and is characterised by its high efficiency.

FREE VORTEX FLOW – In a compressor, the condition when the whirl velocity of a flowing fluid varies inversely as the radius.

FUEL RATIO – The weight of fuel used to heat unit weight of compressed air to the turbine inlet temperature.

FULL ADMISSION – Admission of gas stream over the full blade entry, and this becomes possible when the nozzles subtend the whole blade circumference (annulus area).

FLAME HARDENING – Process of hardening by which steel or cast iron is raised to a high temperature by a gas torch flame and then almost immediately quenched.

FAN (cooling) – The device on the front of the engine that rotates to draw cooling air through the radiator or around the engine cylinders.

FAST IDLE – Engine idle speed when the carburettor fast idle cam is in operation. A mechanism on the carburettor, connected to the automatic choke, that holds the throttle valve slightly open when the engine is cold so that the engine will idle at the higher rpm as long as the choke is applied.

F HEAD ENGINE – A type of engine in which some of the valves are in the cylinder head and some in the cylinder block, giving the F shaped appearance.

FILTER – That part in the air, lubricating oil or fuel system through which air, oil or fuel must pass so that dust, dirt or other contaminants are removed.

FINS (engine) – Thin metal projections on an air cooled engine cylinder and head, which greatly increase the heat radiating surfaces and help cooling of the engine cylinder.

FINS (radiator) – Thin metal projections, over which cooling air flows, that carry heat away from the hot coolant passages to the passing air.

FIRING ORDER – The numerical order in which the engine cylinders fire, or deliver their power strokes begining with No.1 cylinder.

FLYWHEEL – A heavy rotating metal wheel attached to the crankshaft which helps even out the power surges from the power strokes and also serves as part of the clutch and engine cranking system. Acts as power reservoir.

FLYWHEEL RING GEAR – A gear fitted around the flywheel that is engaged by the teeth on the starting motor drive to crank the engine.

FORGED PISTON – A piston made by hammering hot aluminium into a mould of desired shape.

FOUR STROKE CYCLE – The four piston strokes of intake, compression, power and exhaust which make up the complete cycle of events in the four stroke cycle.

FRICTION HORSE POWER – The power used up by an engine in overcoming its own internal friction, usually, it increases as engine speed increases.

FUEL TANK – The storage tank for fuel on the vehicle.

FULL FLOATING PISTON PIN – is one which is free to rotate both in the piston pin bosses and in the connecting rod small end.

FULL FLOW FILTER – Type of oil filter in which all the oil from the oil pump flows through the filter.

FEELER GAUGES – Consist of a number of thin metal blades, each of a different thickness and in the desired number of dimensional steps. They are used for checking clearances.

FIRTHS HARDOMETER – Instrument for measuring the hardness of materials, particularly metals.

FACE PLATE – Flat, slotted plate screwed on the nose of the lathe spindle, or bolted to a flange, to enable work to be machined which cannot be held in the chuck.

FEATHER – A sliding key sometimes called a spline, used to prevent a pulley, gear, or other part from turning on a shaft, but allows it to move lengthwise. The feather is usually fastened to the sliding piece.

FEED STOP – Method of tripping the power feed of a machine tool at a predetermined point.

FIXTURE – Device by which a component to be machined is correctly located and held during a machining operation.

FLASK – Complete moulding box that contains the sand that form the mould.

FOLLOWER REST – A support for long, rather small diameter work to be turned in the lathe. The rest is attached to the carriage and set close to the cutting tool. It travels along with the cutting tool to prevent the work from springing away from the cutting tool.

FOOT STOCK – Part of a dividing head attachment for the milling machine. It contains a center for supporting the workpiece, the same as the tailstock does for a lathe.

FOUR JAW CHUCK – A chuck that provides a more powerful grip on the work by means of four jaws which may be adjusted independently, so that irregular shapes may be gripped, and the fact that the jaws can be reversed enables the work to be gripped inside as well as from the outside.

FEATHER – A sliding key, sometimes called splint. Used to prevent a pulley, gear or other part from turning on a shaft but allows it to move lengthwise. The feather is usually fastened to the sliding piece.

FILLET – A concave surface connecting the two surfaces meeting at an angle.

FLANGE – A metal part which is spread out like a rim, the action of working a piece or part to spread out.

FLANK (Side of thread) – The straight part of the thread which connects the crest with the root.

FLARE – To open or spread outwardly.

FULCRUM – The pivot point of a lever.

FLUSH – When the surfaces of different parts are on the same level, they are said to be flush.

FLUTE – A straight or helical groove of angular or radial form machined in a cutting tool to provide cutting edges and to permit chips to escape and the cutting fluid to reach the cutting edges.

FIXED DISPLACEMENT PUMP – A type of pump in which the volume of fluid handled per cycle cannot be varied.

FINE BORING MACHINE – Machine used for boring to very close limits, the holes in pistons, the bores in cylinder blocks, the bearings in motor car and aero engine connecting rods, valves as fitted to steam and other piping, may have a horizontal or vertical spindle.

FLY BALL GOVERNOR – Conventional type of centrifugal governor, commonly called a mechanical governor.

FORGING MACHINE – Machine designed to shape a metal article while the material is in the hot plastic state by applying the necessary force or pressure.

FISHYBACK – The transportation of highway trailer bodies abroad ship.

FLAMMABLE – A marking on the box to indicate that the contents may easily set on fire or have a tendency to explode.

FLAT BED TRAILER – A flat surfaced platform with wheels.

FLATTENED STRAND WIRE ROPE – A modification of linear contact ropes. During its manufacture, every strand laid from wires of circular cross–section is radially squeezed over the circumference so as to flatten the wires.

FLEX – Flow tank car. A pressurized tank car that can unload in a few minutes.

FLOATING CRANE – A crane mounted on self propelled or towed pontoons, used for salvage work, along shore and offshore duties, crane motions are accomplished with electric drives, commonly of the dc type employing the Ward Leonard control.

FLOW RACK – Rack in which the material can be inserted at one side and will move by gravity to the other where order picking takes place.

FORCE OF GRAVITY – Force decided by the attraction the earth exerts on a body which, unlike the mass, depends on the local value of the acceleration of free fall.

FORK LIFT TRUCK – Equipment designed to pick up, transport, stack and unstack pallet loads.

FOURWAY PALLET – A pallet design that permits entry of materials handling equipment from four sides.

FRAGILE – A marking on the box to indicate that the contents are delicate and breakable.

FACTOR OF SAFETY – The ratio of the damaging stress to working stress.

FATIGUE IN METALS – The tendency in a metal to fail, breaking or cracking under conditions of repeated cyclical stressing that take place well below the ultimate tensile strength.

FATIGUE STRENGTH – The amount of stress that can be applied to a metal without failure while it is subjected to ten million or more cycles of load reversals. In mild steel, the fatigue strength is about 50 per cent of the tensile strength.

FERRITE – Iron practically carbon free. It forms a body centered cube lattice and may hold in solution considerable amounts of silicon, nickel or phosphorous.

FLUIDITY – Ability of molten metal to flow readily, usually measured by the length of a standard spiral casting.

FRACTURE STRESS – The maximum principal true stress at fracture. Usually refers to unnotched tensile specimens.

FREE ELECTRONS – Electrons which are in the outer orbit of the atoms nucleus.

FELLOWS PROCESS – Method of generating involute gear teeth by the use of pinion shaped cutter.

FETTLING – Operation of removing any sand left on the casting from the mould and core, and also the removal of surplus metal that is always associated with castings direct from the foundry, such as runners, risers, feeders and so on.

FILAMENT WINDING – A composite manufacturing process where the end product is to have a hollow internal shape. A filament of the fibre is wound around a form, then bonded in place with the resin matrix.

FILE CUTTING – Incising the teeth on a file blank by means of a mechanically driven chisel of high speed steel.

FILING – Operation of smoothing a rough surface or reducing the thickness of a piece of material with a file.

FITTING – Finishing of mating parts to dimensions which will allow the desired tightness or freedom of movement on assembly.

FLANGING – any process producing a flange. A flange may draw on a shell or a tube.

FLASH WELDING – Method of electric resistance welding of sections of material by the formation of an electric arc between the edges of the pieces to be joined and then pressing together with a light pressure the molten edges.

FLATTING – Finishing operation carried out at the end of the work cycle to remove the various hammer marks on the surface left in by the previous shaping operations.

FLOAT GLASS – A glass manufacturing process that produces a continuous sheet or ribbon of glass.

FORGING – A method of metal working in which the metal is hammered into the desired shape, or is forced into a mould by pressure or hammering, usually after being heated to a more plastic state. Hot forging requires less force to form a shape than that of cold forging, which is usually done at room temperature.

FORM GRINDING – Grinding of tool designed for machining and other operations, in such a way that they are provided with the precise form required for their work, or regrinding them to restore the form after it has been lost as a result of service.

FORMING – Production of shaped part either by means of feeding in a tool ground to shape or form of the part or by what is known as spinning.

FOUNDRY – Place where metal is melted and poured into required shapes.

FULL AUTOMATIC – Process in which all phases, once started, are accomplished without the need of further manual input.

FULLERING – Similar to drawing and is a preliminary forging operation which results in an elongated section between two heavier sections.

FUSION – Merging of two materials while in a molten state.

FUSION SAWING – Sawing material in the cold state by means of friction discs, where a quick and rough cut is sufficient for the purpose.

FUSION WELDING – Welding process in which the metals are brought to the temperature at which they melt, and are joined without hammering.

FLOATING LINK – A link in a mechanism which does not have a fixed center of rotation (e.g., coupler in a four bar linkage).

FORCE – The entity which when acts on a body can cause a change in its velocity or direction or both.

FRAME – That part of a machine which is stationary and which supports the moving parts.

FRICTION DRIVE – Drive in which the rotation of one body causes another body in contact with it to rotate due to sufficient friction between the bodies.

FLARING – Method of forming or preparing the ends of tubing to connect them directly with or through the use of fittings.

FLEXING DISC VALVE – One type of valve commonly used in compressors. It is a one way valve.

FLOODED EVAPORATOR – One that is full of liquid refrigerant at all times. Additional liquid is permitted to enter only to replace that which boils away.

FREEZER BURN – Surface damage due to excessive drying during freezing.

FREON 12 – Refrigerant used in automatic air conditioners. Also known as Refrigerant -12 and R-12.

FROST HEAVE – Refers to the movement of ground as a result of being frozen because of insufficient insulation underneath a cold store.

FUSES – Devices used for protection of electrical circuits, either cartridge or plug type.

FLAME FRONT – The glowing layer of flame that separates the burned charge from the unburned charge in a SI engine during combustion process. The flame front should move in a controlled pattern across the cylinder.

FLAME VELOCITY – is the speed with which the flame front travels inside the combustion chamber. This affects combustion phenomena, development of pressure and production of power.

FLASH OVER – A condition that occurs when a spark jumps across the surface of a spark plug insulator from the terminal.

FLAT SPOT – A point during acceleration when the engine seems to lose power for an instant.

FLOAT BOWL – In the carburettor, the reservoir from which gasoline feeds into the passing air. Also called FLOAT CHAMBER.

FLOAT LEVEL – The float position at which the needle valve closes fuel inlet to the carburettor to prevent further delivery of fuel.

FLOAT SYSTEM – The system in the carburettor that controls the entry of fuel and fuel level in the float bowl.

FLOODED – A term used to indicate that the engine cylinders received an air fuel mixture too rich to burn.

FOUR BARREL CARBURETTOR – A carburettor with four throttle valves. In effect two, two barrel carburettors in a single assembly.

FUEL FILTER – A screen used to prevent contaminants in the fuel from entering the carburettor or fuel pump.

FUEL LINE – The pipe or tube through which fuel travels from the tank to the fuel pump and from the pump to the carburettor.

FUEL NOZZLE – The tube in the carburettor through which gasoline feeds from the float bowl into the passing air. In a fuel injection system, the tube that delivers the fuel into the compressed air or passing air stream.

FUEL PUMP – The electrical or mechanical device in the fuel system which transfers fuel from the fuel tank to the carburettor.

FUEL SCREW – A fine point screw that projects into the slow jet outlet passage, used to adjust the fuel mixture at slow speeds, located at the engine side of the carburettor.

FUEL SYSTEM – In an automobile, the system that delivers to the engine cylinders, the combustible mixture of vaporized fuel and air. It consists of fuel tank, lines, gauge, carburettor, fuel pump and intake manifold.

FULL ADVANCE – The point at which the advance unit will no longer continue advancing ignition timing.

FULL THROTTLE – A wide open throttle position with the accelerator pressed all the way down to the floor board.

FEED WATER – The water (chemically treated water) supplied to a boiler to replace that evaporated as steam or blown off.

FEED WATER HEATER – An apparatus for raising the temperature of boiler feedwater by abstracting some of the heat from exhaust steam or from the hot gases of combustion.

FEED WATER REGULATOR – An automatic device which controls the amount of feed water admitted to the boiler so as to maintain a constant water level in the boiler drum.

FIREBOX BOILER – Boiler having the fire within a firebox, although external to the shell, is rigidly connected to it.

FIRE CRACKS – Cracks caused by radiant heat, usually around circumferential riveted seams of thick plates.

FIRE LINE – The highest point of the heating surface in most common types of boilers.

FIRE TUBE – Tube in which the products of combustion pass through and water surrounds the tube.

FLASH BOILER – A boiler consisting of a series of coils of steel tubing, water is supplied by a pump to the top coil, from where it circulates through the other coils, becoming heated in its descent and issuing from the lower coil, as highly superheated steam.

FLUID VAPOURIZER GENERATOR – A closed vessel in which a heat transfer medium, other than water, is vaporized under pressure by the application of heat.

FOAMING – It is severe priming or agitation of the water level due to dirty or impure water. Small, stable, non-coalescing bubbles are formed through the boiler water.

FOULING – A condition of the flue gas passages in a boiler or furnace that adversely affects the transfer of heat, usually in the form of soot or scale.

FURNACE – That part of the boiler designed for burning the fuel.

FUSIBLE PLUG – A safety device which acts in case of dangerously low water. It consists of an alloy of tin, lead and bismuth and a covering of brass or cast iron. The plug melts during dangerous water levels and permits steam to rush into the furnace and put out fire.

FULL ADMISSION TURBINE – A steam turbine in which steam is admitted over the entire circumference of the blade annulus. Reaction turbines are full admission turbines.

FACTOR OF EVAPORATION – A quantity which when multiplied by the amount of steam generated at a given pressure from water at a given temperature, gives the equivalent evaporation from and at 100°C.

FLOW WORK – The product PV (pressure and specific volume) represents flow work in a steady flow system.

FORCED CONVECTION – Circulation of the fluid is made positive by some mechanical means such as a pump for water or a fan for hot gases.

FORCED DRAFT COOLING TOWER – Cools water by mechanically forcing air through the water spray in the tower.

FREE EXPANSION – is a process wherein a fluid from a pressure chamber expands into a vacuum chamber through an orifice of large dimensions.

FREEZING POINT – The temperature at which water turns into ice (0°C at sea level).

FROM AND AT 100°C – In boiler operation, it is an evaporation that would be the equivalent of the actual evaporation when the feed water enters the boiler at 100°C and steam is formed at 100°C, at standard atmospheric pressure.

FROSTING EVAPORATORS – Those evaporators which always operate at temperature below 0°C.

FUNDAMENTAL DIMENSIONS – Internationally accepted units are time, length, mass, force and temperature.

FINAL DRIVE RATIO – The number of times the transmission output shaft turns to produce one revolution of the rear wheel.

FINAL DRIVE SYSTEM – The part of the drive train that uses a chain, belt or shaft to direct the power flow from the transmission to the rear wheel.

FORK SLIDERS – Lower portion of fork which slides over the fork leg.

FORK TUBES – Long sturdy tubes attached to triple clamps and fitted inside fork sliders.

FRAME – The skeleton of the two wheeler made of tubes, steel plates or pressed steel that supports the rider and engine and provides attachment points for the frame components.

FRONT FORK – The spring and damping device that holds the front wheel in place.

FUEL PET COCK – An on-off valve located at the bottom of fuel tank. It may provide for reserve fuel supply and may have a filter screen and sediment bowl. Fuel line to carburettor is attached to fuel petcock.

FACE SHIELD (eye protection) – Device positioned in front of the eyes and over all or a portion of the face to protect the eyes and face.

FILLET WELD – A weld of approximately triangular cross-section joining two surfaces approximately at right-angles to each other in a lap joint, T joint or corner joint.

FILLER METAL – Metal to be added in making a welded, brazed or soldered joint.

FIRE CRACKER WELDING – Shielded metal arc welding process in which a length of covered electrode is placed along the joint in contact with the work-pieces. During welding, a stationary electrode is consumed as the arc travels the length of the electrode.

FISH EYE – A discontinuity found on the fracture surface of a weld in steel. It consists of a small pore or inclusion surrounded by an approximately round bright area.

FLOW WELDING – Process which produces coalescence of metals by heating them with molten filler metal poured over the surfaces to be welded until the welding temperature is attained and until sufficient filler metal has been added.

FLUX – Material used in welding to prevent, dissolve or facilitate removal of oxides and other undesirable surface substances.

FLUX CORED ARC WELDING – Process in which coalescence of metals is effected by heating them with an arc between a continuous filler metal (consumable) electrode and the work. Shielding is by the flux contained within the tubular electrode.

FLUX CORED ELECTRODE – A composite hollow filler metal electrode containing within it ingredients to provide such functions as shielding atmosphere, deoxidation, arc stabilization and slag formation.

FOREHAND WELDING – A welding technique in which the welding torch or gun is directed toward the progress of welding.

FORGE WELDING – Process that produces coalescence of metals by heating them in air in a forge and by applying pressure or blows sufficient to cause permanent deformation at the surface.

FUSION – Melting together of filler metal and base metal (substrate) or of base metal only which results in coalescence.

FUSION WELDING – Arc welding process that uses fusion of the base metal to make the weld.

FUSION ZONE – Area of base metal melted as determined on the cross-section of a weld.