6.6- Pipes and Unions Flashcards
What does a tube assembly consist of
The tube and tube fittings
What are the dimensions determined by
Their dimensions are determined by the external diameter 1/8 inch increments and wall thickness
What pressures are high and low lines and what is the third type.
High lines are over 1500psi
Low pressure lines are below 1500psi
Suction and return are the third type
What lines must be made of steel
Lines in the engine area, where there is a danger of fire, and in the landing gear area, where there is a danger of being hit by stones
Why are titanium lines an exception
Due to reasons of weight
What items of information are stencilled on the pipe or surface stamped
Drawing or part number, inspection stamp,test stamp and date of manufacture
What is the name for the c de system and how does it work
ATA100
The system
The component it is fitted to
The subsystem to which the pipe is fitted
Whether it is a suction, pressure or return line
If you saw phdan what would this mean
Pipelines with physically dangerous contents, due to temperature, noxious, corrosive etc.
How do flareless fittings achieve their seal
Ball bush principle
Describe an MS fitting
The sleeve of malleable steel is shaped by pre stressing in such a way that it’s inner cutting edge is pushed over the pipe to seal it. The tube must, in principle, be on the stop support
Name some key things about a Harrison fitting
Ball Bush fitting
Tube is moulded, in that it is swaged in sleeve for a tight seal.
Ease of handling and simple tools for installation
Thin walled tubes and almost totally vibration resistant
Permaswage fitting
Repair fitting for damaged pipes Steel sleeve is squeezed onto the prepared pipe End with a hydraulically driven tool Quickly in situ Light and gives a good seal Cannot be separated
For a flare type fitting to work what must the surfaces be
Scrupulously clean and free of cracks, scratches and nicks etc
Flare angles for aircraft fittings and vehicle type fittings
Aircraft have a angle of 37.
Vehicle type have an angle of 45.
Leak inspection
If a leak is apparent from a correctly tightened joint, it should be dismantled and mating surfaces thoroughly inspected for damage or debris.
What mustn’t you do in attempt to fix a leak
Over tighten the joint
What are two types of flare
Single and double
What types of single flare are there and what is special about them
Impact type- 37 angle at hydraulic tube end to ensure an effective single seal point between the nose of the triple lok flared tube fitting and the tube
Roll type- preferred method with an entirely self contained unit producing a good flare. No hammering required
Describe the double flare
Soft aluminium tubing
Outside diameter of 3/8 inch or smaller
Smoother and more concentric = better seal
More durable
Name and describe tube damage types
Sharp bottomed surface defect- loss of material where the damage cuts into the material to form a sharp edge at the deepest point e.g. scratch
Round bottom- defined as damage with loss of material, although the damage on the bottom is not sharp edged e.g. abrasion points
Round bottom impact- dent in the tube walling
When is damage not permitted
When it isn’t in the manual
General information about hoses
Must be certain amount of slack, between 2 and 4%
Twisted hoses have a shortened life
When are hoses used
Connect stationary to moving parts in areas of high vibration
What are the three types of hose ratings and what are their values
Low pressure- up to 600psi
Medium pressure- up to 3000 psi
High pressure- above 3000 psi
