Maintenance Practices M7.9 Flashcards
How are tube sizes dertermined
External diameter and wall thickness
When is aluminium used for solid tubes
Low pressure lines or 1500psi or lower
When manufacturing pipes how would they be tested
To 1.5 times system pressure
When installing bonded clamps what must be remembered
All surface protection and paint must be removed to ensure good bonding
Aircraft pipe flares are what angle
37°
What must you do if there is a slight leak in a joint
Do not over tighten. Back off, clean and retorque to ensure nothing is damaged
What tool is preferred to flare pipes
Roll type tool 37°
What pipes would you find a double flair
Soft aluminium tubing 3/8 diameter or smaller
What is Harrison type suage fitting
Well suited for thin walled tubes and vibration resistant
What is a permasuage fitting
Permanent and not separable.
Big disadvantage you can’t disassemble
What is done to help reduce stress when bending pipes
Lubricate the bending portion
What is used to calculate bends other than simple 90°
Offset bend calculator
What must be mindful when replacing aluminium pipes for CRES or titanium if allowed
There will be a weight penalty
What is permissible damage in sharp bottom defects in solid pipes
5% wall thickness or scrap
What is permissible in round bottom defects
10% wall thickness or scrap
How much will flexible hoses reduce by when under pressure
2-4%
When flexible hoses are manufactured wha is done to compensate for hoses shrinking slightly whilst under pressure
They are manufactured 5-8% larger than required
What are flexible hoses used for
Connecting moving parts to stationary parts
What are the only reusable couplings allowed
Aeroquip
What are lay lines used for
To make sure hoses aren’t twisted on installation
How often must flexible hoses be supported
Every 24 inches minimum
If minimum bend radius cannot be met what is permissible to be done
You can fit an elbow
