6.6 Pipes and Unions✅(6) Flashcards
What material is generally used for low and medium pressure rigid lines
aluminium alloy
How is the size of rigid tubing determined
outside diameter
The wall thickness of rigid tubing determines what
its strength
What fluid line would be identified by red tape with a star
- Fuel
What is the flare angle of a aircraft fitting
37*
What is the flare angle of a automotive fitting
45*
In a vibration resistant, thin wall tube Harrison flareless fitting, how is the sleeve attached to the tube
It is swaged from the inside
What is commonly used as a repair system for repairing hydraulic lines on aircraft
swaging fittings (permaswage)
Medium pressure hoses have a seamless inner liner with what
a reinforcement of 1 layer of cotton braid and 1 layer of stainless steel
What flexible tube liner is the best to carry petroleum based products
Buna-N
What are metal tubing also referred as?
Rigid fluid lines
What are flexible hoses made out of
Synthetic compounds
Where are rigid tubing used?
- stationary applications
- relative,y straight
Where are flexible hoses generally used
- vibration areas
Steel fluid lines are increasingly being used as what?
Pressure fluid lines
Pressure over 1500PSI is ?
High pressure lines
Pressure under 1500PSI is
Medium pressure lines
Suction and return lines are
Low pressure lines
What are medium and low pressure fluid lines preferably made of?
Aluminium alloys for weight saving
In crucial areas what must the pressure lines be made out of
Steel
The size of rigid tubing is determined by ?
Outside diameter
What are the size increments of rigid tubing
1/8inch (3.16mm)
What does the wall thickness of a tube determine
It’s strength
All pipes are marked with a part number, drawing number, inspection stamp, test stamp, date of manufacture (T OR F)
T
Pre made pipe identification can be stencilled on the pipe or surface ink stamped (T OR F)
T
How are fluid lines in aircraft often identified
- by tape or a decal made up of colour codes, words, and geometric symbols
Fluid lines in an oily, hot, or cold environment can use what instead of tape or declas
Steel tags
Why is paint used on fluid lines in the engine compartment
Tape or decals could be sucked into engine system
What is a pipe connector ( union)?
Threaded fitting which allows the pipe work to be separated and reconnected
What does a flared tube fitting consist of
- a sleeve and a flare nut
What are the 2 types of flares used in aircraft piping systems
- single flare
- double flare
What does AN stand for
Army & Navy
What does AC stand for
Air Corps
What is the main difference between AN fitting and AC fitting
AN has a shoulder between the end of the threads and the flare cone
What is another difference between AN fitting and AC fitting
AN body length is longer than AC body length
What are flared tube fittings made of
Aluminium alloy, steel, or copper based alloys
AN steel fitting is what colour
Black
AN aluminium fitting colour is what
Blue
What are flareless tube fittings
- attach 2 sections of pipe together and commonly have ferrules or a sleeve in them
Which flareless fitting is more commonly used today
MS (military standard) fitting
What 2 materials are flareless fittings made out of
Aluminium alloy
Steel
How can a flareless fitting made of aluminium alloy be identified
Green colour
What is the common repair system for repairing hydraulic lines
Permaswage fittings
Are swaged fittings permanent ?
Yes
Where are swaged fittings usually used
To join hydraulic lines where routine disconnections are not required
What is the latest development of a swaged fitting
Permalite fitting
Flexible lines generally consist of an inner liner which carries the fluid, covered with layers of reinforcement to provide strength (T OR F)
T
What are the 4 synthetic compounds used in the construction of the inner liner
- Neoprene
- Buna-N
- Butyl
- Teflon
What is Neoprene suitable for
Petroleum based fluids
What is Buna-N suitable for
- carry petroleum products (better suited)
What is Butyl suitable for
- carry phosphate ester base hydraulic fluids such as skydrol
What is Teflon suitable for
- compatible with nearly every liquid
What is Teflon’s operating temperature
-240c - 204c
Hoses tend to increase in diameter and decrease in length when pressure is applied ( T or F)
T
The outer cover of a hose is often designed as an integral fire sleeve to provide extra protection (T OR F)
T
What are lay lines for
- identify the hose
- indicates if it is twisted or not
The size of a flexible hose is determined by its inside or outside diameter
Inside diameter
Up to 600psi (4000kpa)
Low pressure
Up to 3000psi (20000kpa)
Medium pressure
Over 3000 psi (20000kpa)
High pressure
Can you re use swaged fittings
No
What should you do when aircraft fluid lines are disconnected or removes
- Use blanking caps
What are swivel fittings
Allows the coupling and hose connection to rotate, which prevents twisting, kinking and excessive bending
Quick disconnect couplings provide self sealing action and can be done by one hand (T OR F)
T
V-couplings come in 2 types which are
- v retainers
- v bands
When are worm gear hose clamps (jubilee clips) used
Secure a hose, while remaining connected to a fitting
Worm drive clamps are manufactured from what
- zinc plated steel
- stainless steel
Are v-retainers inexpensive
Yes
