7.9 Flashcards
What are the 4 processes to form a pipe?
- cutting
- bending
- flaring
- belling
Metal piping is sized by outside diameter measured in?
1/16 of an inch
Hacksaw preferably 32 TPI should be used to cut pipes (T or F)?
True
When cutting pipes, how much extra should you leave and why?
- 10%
- to allow for any bends etc
What is recommended before bending pipes?
- lightly lubricate
2 types of flares for piping are?
- single
- double
Explain swage fitting / Harrison-type?
- moulds a sleeve by widening pipe
- well suited for thin walled pipes
- almost totally vibration resistant
Explain permaswage fitting?
- steel sleeve squeezed onto prepared pipe end with hydraulically driven tool
- can be made quickly, light, good seal
- cannot be separated (disassembly problem)
Explain belling pipes?
- allows rubber hose to slip over end and held in place by a screw-type hose clamp
High quality materials for pipes result in thinner walls, larger inner diameters (T or F)?
True
> 1500 psi
High pressure
<1500 psi
Medium pressure lines
Suction and return lines?
Low pressure lines
Scratches or nicks not deeper than to repair
- not deeper than 10%
Up to 600 psi?
- Low pressure
Up to 3000 psi?
-Medium pressure
> 3000 psi
- High pressure
Examples of protective sleeves?
- Heat shrink
- Nylon spiral wrap
- Teflon
What do you do when inspecting for aircraft pipes and hoses?
- use suitable torch
- look for any signs of leaks
- wear or tear
What are support clamps?
- secure fluid lines to aircraft structure or in engine nacelle
The 2 most common encountered clamps?
- rubber cushioned clamp
- plain clamp
What are rubber cushioned clamp?
- secure lines subjected to vibration
- prevents chafing
What are cushioned clamps used for?
- areas that are subject to contamination (e.g. fuel, hydraulic fluid etc)
- highly resistant to deterioration
What are bonded clamps?
- secure fuel, oil or hydraulic lines made from metal
- Has electrical lead so it can be grounded (earth line)
Where do you apply lubricant to get the highest possible load on the contact surfaces?
- Male thread
Pipes are subject to flexing + expanding due to thermal expansion (T or F)?
True
When fitting hose assemblies, it’s recommended that they are supported every?
- 60cm (24 inches)
Hoses are tested to x1.5 load capacity (T or F)?
True
