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pipes and tubes used for
Fluids
Hydraulic oil
Engine oil
Fuel
Potable
​Waste water​
Gaseous
Oxygen
Nitrogen
Extinguishing agent
air
Bleed air
Conditioned air
Static instrument air
Pitot instrument air
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AFIQ ZULKIFLI
FARIS ROSDI
ZAMZI BAIN
WAFI IMRAN
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IDENTIFICATION OF TUBING
Rigid Tubing Identification
Most fluid, gas lines and ducts are marked to identify systems on which they are installed. location of coding will vary according to the length of the assembly.
IMPORTANT POINTS :
- Hose assemblies in phylon and pod areas are not colour coded.
- Heating and ventilation flexible air ducts are identified by part number only and not coded.
- Lines and ducts which are subject to temperatures exceeding 260 Celcius are identified by part number only and are not coded.
- Static and pitot system hose are identified, by functioning as well as system, with a marker of white acetate tape imprinted with function.
- Hydraulic lines have additional marking to identify function and direction of fluid within each line.
- No identification is requaired on lines installed in integral fuel tanks.
RIGID PIPE CONNECTIONS
what it is ??
Sections of rigid tubing can be joined to another tube or to a fitting by several methods. Examples like single and double-flare connectors, fareless connectors, or a hose and clamps over a beaded tube.
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Most common ones, made of steel or aluminium alloy. Type of fitting used determined by :
- the pressure range
- the routing
- the material being used by the lines.
Fitting made of the same material as the original.
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Furthermore, precaution must be taken to prevent dissimilar metal corrosion.
TUBING FLARING
Tubing Flaring
Most modern aircraft is connected to other tubing or to components by flaring its end using flare-type fittings.Use the correct flaring tool.AN fittings flared with 37 degree angle.AC fittings with 35 degree angle.
Double Flare
Tubing made of 5052-0 and 6061-T aluminium alloy in sizes from 1/8 to 3/8 inch outside diameter should be flared with a double flare.Double flares smoother than single flares and more concentric effect when the fittings are torque.
Single Flare
Single Flare
FLARED TUBE END FITTINGS
There are 2 types of nuts that may be used on a flared tube, single piece AN817 nut and the two-piecec AN818 nut and AN819 sleeve
AN817 nut (single piece)
-> Cannot be used on tubing where there is a bend near the end.
AN818 nut & AN819 sleeve (two-piece)
-> AN818 nut & AN819 sleeve combination is the perfect type of connector.
-> why ? because it lessens the possibility of reducing the thickness of the flare by the wiping or ironing action when the nut is tightened.
-> no relative motion between the fitting and the flare when the nut is being tightened.
FLARED TUBE FITTING COLOURS
The Colours
BLACK = Steel tube fittings
BLUE = Aluminium alloy fittings
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REMEMBER
On rigid tubing, the outside diameter is measured in increments of 1/16 inch.Therefore, the matching nut for s tube diameter of 1/2 inch is, as an example AN818-8 nut.
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MS FLARELESS FITTINGS
Fluid lines used in the high-pressure hydraulic and pneumatic systems are so hard they are difficult to flare without cracking,so a system of flareless fittings has been developed.
Consist of a body or a fitting,a sleeve,and a nut.
Inside of the fitting has a smooth counterbore into which the end of the tube fits
Taper at the mouth of the fitting provides the seal between the fittings and the sleeve
The seal between the sleeve and the tube is provided by the bite of the sleeve into the tube.
Attached to the end of the metal tubing by presenting the sleeve on the tube.Presettingh puts enough pressure on the fitting to deform the sleeve and cause it to cut the outside of the tube​
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HMS FITTING
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BRAZED SLEEVES & FITTINGS
The connections of tubes are often brazed which means the sleeve is brazed on the tube.
swaged tube fittings
Modern aircraft that have high pressure hydraulic and pneumatic systems often use swaged fittings.
The fitting is swaged or force into the tube by hydraulic pressure acting on dies.
Portable swaggering tools are available that allow a technician to make permanent repairs to fluid lines installed in the aircraft.
swagging tool
swaged fitting
FLUID LINE FITTINGS
The size of fittings is indicated by the dash numbers following the MFG number of the fitting, these dash numbers are in 1/16 inch.
Example, a -8 fitting is for 1/2 inch tube.
The size of pipe fittings relates to the inside diameter of an iron pipe that has threads on its outside.
Pipe Fittings
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Many of the fitting that connected a fluid line to a component such as a pump or valve have tapered pipe threads on the end that screw into the component.AN816 nipples as shown in Figure 8 has on one side the tapered pipe thread and on the other end the standard flare cone and thread that fit an AN818 nut.When installing a fitting having pipe threads,start the fitting into the hole ffor about one turn,and then put a small amount of thread lubricant on the second thread from the end.Screw the fitting into the hole and tighten it snugly.If the fitting is being screwed into an aluminium casting,it is possible that over tightening can cause the tapered threads to crack the casting.
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uNIVERSAL OR bULKHEAD fITTINGS
Some components, such as selector valves and actuator cylinders use fittings with double threads such as those on the AN804 Tee as shown in Figure 8.A nut is screwed onto the fitting above the cutout portion of the threads.ATeflon ring and an O-ring gaskets are slipped over the end threads and into the groove.The fitting is screwed into the housing until the O-ring contacts the housing and then srewed an additional amount needed to properly align the fitting with the lines that are to connect with it.Hold the fitting with the lines that are to connect with it.Hold the fitting and turn the nut down until it contacts the housing.This willforce the O-RING INTO THE CHAMFERED edge of the hole to provide the fluid tight seal.
AN and AC Flared Tube Fittings
Flared tube fittings are available in many configurations.The  AN816 nipple and AN822 elbow are used to connect a flared tube or a flexible hose to a component with tapered pipe threads.The AN821 elbow and AN815 union are used to join flared tubes or flexible hose. The AN820 cap and AN806 plug are used to seal lines and fittings to keep dirt and contaminants out of the system.
AC Flared Tube Fittings
Many of the airplanes built during World War II used AC fittings which are similar to the AN fitting.however , there is enough difference that they are not interchangeable.AN fittings have a short shoulder between the end of the flare cone and the beginning of the threads .The older AC fittings do not have this recess.Steel AN Â fittings are coloured black,and aluminium alloy AN fittings are coloured blue. AC fittings are coloured either gray or yellow.AC fittings are seldom used these days.
BOBBINS
#Often used in hydraulic systems
#used to assemble different component to transfer fluid
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Installation of the O-ring,the square seal and the back up rings
HOW TO INSTALL???
NOTE!!!
!DO NOT INSTALL PARTS ARE DAMAGES
!INSTALL THE PARTS IN CORRECT SEQUENCE:
*Install back up rings in the grooves before install the seals
*install the o-rings on the identification grooves side of bobbins(manifold side)
*slide the o-rings onto the slevess until it touches the end
*make sure in the correct position and without any torsion and damages
REMINDER!!!
-If apply lubricants, apply it in nesssary amounts and apply it minimum 1/4 of an hour before apply on the robbins
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Quick-disconnected fitting
It used in hydraulic systems without running engines.supplied by ground-power unit (gpu).To prevents loss of fluid from lines to pump fitted with quick disconnect fit
When it disconnected, springs inside both halves of the fitting pull the poppet vavles tightly into their seats and seal-off lines.when it connected,plungers in each  fitting meet and force the poppets of theirs seats allowing fluid to flow freely through the fittings
Flexible Fluid Lines
They carry :
*Hydraulic fluid
*oil
*fuel
*water
*oxygen
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(1)FLEXIBLE HOSE CONSTUCTION AND MATERIAL
* Consist of inner and outer liner cover
*butyl rubber/synthetic(silicone)
-stainless steel reinforcements
-meet system requirements of low,med,high pressure
*hoses used with petroleum,inner made from synthetic rubber,outer braid is grey black
*hoses with phosphate ester fluids,inner made from synthetic butyl rubber and outer is braid green
*landing gears used high pressure hoses with corrosion resistant fitting
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(2)FLEXIBLE FLUID LINE INDENTIICATION
LAY LINE
MARKED WIYH YELLOW WHITE BLACK AND RED STRIP FOLLOWED BY INFORMATION TO IDENTIFY THE HOSE:
*Specification number
*manufacturing name or symbol
*year and quarter of manufacture
*dash number
*additinal infos
SIZE DESIGNATIONS
Refers to the outside diameters of a rigid tube that has equivalent flow charasteristic.EX:-8 or (8/16) tubing inside diameters not exactly 1/2 it more smaller for the tube wall thickness
TYPE OF FLEXIBLE PIPES
There are many types of pipes been make depends on amount pressure it withstand.LOW,MED,HIGH...
LOW PRESSURE HOSE
-Mainly used for low-pressure instrument of air
-made with seamless inner tube and made of a single layer of cotton braid
MEDIUM PRESSURE HOSE
-made with seamless and cotton braid impregnated with a rubber to secure bond inner side
HIGH PRESSURE HOSE
-more steel braids used compare to low and high pressure hose outer cover hose is smooth
-hoses with petroleum products inner is made of synthetic rubber and cover is black and with yellow lay line
-hoses with skydrol the ineer is made of synthetic butyl rubber and outer is green and lay line is white
TEFLON HOSE
-inner o teflon cover with stainless steel braid for medium pressure or with double spiral wrap for high pressure
*TEFLON NOT AFFECTED BY
-fuels
-oil
-coolants
-solvents
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(3)FLEXIBLE HOSE END FITTINGS
May be equipped with either swaged or replaceable end fittings
Recplaceable end fittings consists of three pieces
A nut
A nipple
A socket
FUEL LINES​
Made from stainless steel
Where hose are required, it must be made out of fire resistant material
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​FUEL SYSTEM COUPLINGS
Fuel pipe ends are flared to accept the specified type of coupling
Standard pipe coupling are available in sizes up to 2.5 inches
Its often in aircraft fuel system
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(4)FLEXIBLE COUPLINGS
Can be used as connections in aircraft fuel, potable water, oxygen and environmental control systems
GAMAH COUPLING
A precision item used in all type of aircraft, missile and space systems. They are mostly used in fuel system.
PNEUMATIC AND AIR SYSTEM PIPES
Mainly used to transfer air from one point to another point.
DUCT
Carry different sorts of air to and from various system
Engine bleed air ( HIGH & LOW PRESSURE )
De-icing system
Air conditioning
Cabin pressurisation
Ventilation
Ambient air
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MADE from :
Stainless steel
Titanium
Aluminium alloy
V-CLAMPS AND COUPLING
Used in engines bleed pneumatic bleed system, pressurisation and air conditioning.
Usually consist single metal clamp and precision formed metal flanges​
Some coupling provide metal to metal seal without use gasket
So, it can be repeatly disconnected and reconnected without affecting its design leakage rate
FLANGE AND SLEEVE COUPLING
Often used where the ducts move due to temperature, pressure or structural motion
Equipped with one or two gasket
Two cables or rod installed to prevent the ducts from slipping
SREW TYPE HOSE CLAMPS
Hose Clamps Installation
Joined with the rubber hose slipped over the ends of tube and held in place
The end of tubes being joined must be beaded
The hose clamps are centred between the ends of the hose and the beads
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