6.6 Flashcards
Where are flexible hoses generally used?
With moving parts or hose is subjected to vibration
(Landing gear typicaly use both)
Why was copper tubing stopped being use in early aircraft?
Became hard or brittle from vibration
Ridgid tubing is used in stationary applications and long straight runs what systems typically use rigid tubing?
Fuel, oil, oxygen and some instrument systems
What systems do aircraft landing gear use?
And why?
Both types rigid because of durability of metal and flexible for the gear extension and retraction
What does a rigid fluid line assembly consist of?
The tube and both tube fittings
How are rigid fluid lines dimensions determined and what are increments do wall thickness go up?
Rigid tubing is measured by its external diameter and goes by 1/8 inch increments
If the material quality is higher what same pressure can be achieved with a loss of?
Wall thickness material can be reduced since the material is stronger
What material over aluminium is being used for fluid lines since it allows greater operating _____ and longer ________ _______?
Steel fluid lines
Operating saftey
Longer life expectancy
What is the pressure/use of High, Medium and low pressure lines?
High- Over 1500 PSI
Medium- Up to 1500 PSI
Low- Suction and return lines.
What material are medium and low pressure fluid lines preferably made of for weight saving?
Aluminium alloys
Fluid lines near engines in danger of fire and landing gear danger of stones must be made of what?
And what is the substitution and why?
Steel
Or Titanium for weight saving
What must fluid lines match and be free of so they maintained there necessary seal over longer operating periods?
Must match their axis and be free of tension.
Neoprene pipes is suitable for what?
Petroleum based fluids
Aircraft fittings have a flare angle of?
Automotive is?
37 degrees (aircraft)
45 degrees (Automotive)
What is Butyl suitable for?
Hydraulic fluid (e.g skydrol)
What is a swaged fitting
And how do you take it out
Permanent fitting line used where quick disconnect are not required
Cut it out to remove
What is a swivel fitting
A fitting that allows flexability and movement
What increments is rigid tubing and flex tubing measured in?
Rigid- 1/8
Flex- 1/16
What 2 methods can pipes be marked?
Stencilled or surface ink stamp
What colour is 1100 aluminium alloy?
White
What colour is 3003 aluminium alloy?
Green
What colour is 2014 aluminium alloy?
Grey
What colour is 2024 aluminium alloy?
Red
What colour is 5052 aluminium alloy?
Purple
What colour is 6053 aluminium alloy?
Black
What colour is 6061 aluminium alloy?
Blue and Yellow
What colour is 7075 aluminium alloy?
Brown and yellow
In areas oily, hot or cold where tape or decals can’t be used what is used instead
Metal tags
What is a threaded fitting that allows pipe work to be separated and reconnected without causing deformation to the pipes?
Pipe connectors/ unions (mainly used in hydraulic and fuel systems)
What does a flared tube fitting consist of?
A sleeve and a flare nut (this prevents damage to the flare and provides strength and support)
What are single flares formed with?
Why do single flares have to be manufactured to specific tolerances?
A impact type flaring tool
Ensure a strong, leak-free joint
Any aluminium tubing under ___ of a inch can be double flared it provides a better seal
If made too small or big what can happen?
3/8 of a inch or under
Small leak or pull apart
Big interfere with installation
If a fitting leaks when torqued what should you do?
Flare and fitting must be inspected
What tool is used to double flare a tube? (Man)
Manual flaring tool
What are AN and AC fittings
AN-Army and Navy
AC-Air Corps
What spec fitting was the majority in early aircraft?
AC- Air Corps
What is the difference between AN and AC
Main point AN is longer and has shoulder
AN has a shoulder between the thread and flare cone <=:::: (AN gap before thread) <::::(AC)
and AN is longer
What colour are AN steel fittings and aluminium
Steel-Black
Aluminium- Blue
What are the 2 types of flareless connectors?
And what is similar but different with them?
MS and Harrison same thread but not interchangeable
ba are posh cunts
Yes they are
Raony is the goat
Of course
What is special about a MS fitting
Pre stressed shape inner cutting edge is pushed over pipe to seal
What is special about a Harrison fitting?
Ball-bush fitting as seal and not moulded
Suited well for thin walled tubes and vibration resistant.
What parts do the Harrison fitting consist of?
The Tube, Sleeve and Nut
What commonly used repair system is for repairing hydraulic lines on aircraft?
Permaswage fittings
What identification is 5 in a MS fitting?
Corrosion resistant steel (CRES)
What identification is 4 in a MS fitting?
Cadmium Coated
What identification is 4 in a MS fitting?
Cadmium Coated
What identification is D in a MS fitting?
Anodised
What are flexible fluid lines called and what are they constructed of to provide flexibility?
Hoses
Synthetic componds
What are flexible fluid lines used for?
Aircraft fluid systems to connect moving parts to stationary
What 3 properties/constructiom do flexible fluid lines consist of?
Inner liner
Layers of reinforcement
Outer cover
What is Buna-N used to carry?
Petroleum based liquids
What is an advantage of Teflon inner liners?
Broad operating temps -240 C to 204 C
What pressure is low-pressure hoses?
Up to 600psi
What pressure is medium-pressure hoses?
Up to 3000psi?
What pressure is high-pressure hoses?
Over 3000psi
