Pipes And Unions Flashcards
(40 cards)
Aircraft fluid lines
Made of metal tubing or flexible hose
Dimensions determined by
External diameter (1/8”) Wall thickness
Pressure categories
High = 1500 psi Medium = under 1500 psi Low = suction and return lines
Pressure tested
1-1.5 times normal working pressure
Identification
ATA system Stencilled or stamped - Drawing Number or Part Number - Inspection stamp - Test stamp - Date of manufacture
Two identification systems
Colour and symbol
Code(ATA 100 number system)
Fittings
Joint tubing to each other and components in various types and sizes to cater various pressures.
Flareless (Ball Bush)
Sleeve of malleable steel shaped by pre stressing in a way that it’s cutting edge is pushed over the pipe, securing it.
Not reliable
Cannot be re tightened
Flareless (Harrison)
Pipe swaged in the sleeve to form a tight seal
Special tool moulds sleeve and widens pipes
Vibration resistance
Flareless (Permaswage)
Repair fitting for damaged pipes Sleeve squeezed on using hydraulic drive tool Quick Light, good seal Cannot be separated
Flared fitting
Complicated to manufacture Vibration resistance Tool used to make flare 37 degrees flare is used in aircraft If a leak is found dismantle and inspect
Single flare (impact tool)
Hammer and impact tool
Plunger hammered in
Plunger rotated
Must be within 1” tube = 0+-0.01”
Single flare (Roll type)
Rolling action
Self contained unit
Flare cone turned into pipe
No hammering
Double flare
Soft aluminium outside diameter 3/8” or smaller
Smoother, better seal
More durable
Sharp damage
Loss of material damage cuts into material to form
Round bottom
Loss of material damage at bottom is not sharp edged but rounded
Round bottom impact
Dent in the pipe working
Hoses
Produced by manufacturer
Same id as pipes
Requirements for pipes
Amount of slack (2-4% diameter increase under pressure)
Never twisted
Ratings
Low pressure = 600 psi
Medium pressure = 3000 psi
High pressure = over 3000 psi
Lay lines
Along length of hose Twist indicators (yellow,red,white)
Inspection of pipes
Designated intervals
Deterioration
Leaks
Mechanical damage
Construction of pipes (inner layer)
Chemically compatible Neoprene - petroleum based Buns N - petroleum based Butyl - hydraulic fluids Teflon - almost all fluids
Construction (reinforcement)
Determines strength
Cotton, rayon, polyester
Carbon steel, stainless steel wire braid
