General 2 Flashcards
(49 cards)
Name the parts of a military standard flareless tube fitting
-body
-sleeve
-nut
What type fitting materials should be used with stainless steel tubing?
Stainless steel
What is the purpose of a sleeve on a flared tube connection?
The nut and sleeve together when tightened will draw the sleeve and tubing flare slightly against the male fitting to form a tight seal
What happens to a flareless tube fitting when it is over tightened?
The nut drives the cutting edge of the sleeve deeply into the tube, causing the tube to be weakened
What are the identification markings usually found on flexible rubber hose?
-Lay line
-hose size
- Date of manufacture
- Pressure and temperature limits
Name at least two synthetic material materials commonly used in the manufacture of flexible hose
- Buna-N
- Neoprene
- Butyl
- ethylene propylene diene monomer (EPDM)
- Teflon
When selecting a flexible hose for use in phosphate Ester based hydraulic fluid system, the hose should be made of which synthetic rubber compound?
Butyl
What is the maximum interval for repeating the required markings on a flexible hose?
No more than 9 inches along the length of the hose
What percentage of flattening is allowed when bending metal tubing?
No more than 75% of the original diameter
How can you determine if a fitting is an AN type rather than an AC type?
AN fittings have a shoulder
AC fittings do not have a shoulder
What are the most significant differences between AN and AC fittings?
- Sleeve length
- Thread pitch
- the shoulder between the threads and the flare cone on AN fittings
How do you tell a flareless fittings from a flare type fitting?
Flareless fittings don’t have a flare cone, and there is no space between the threads and the end of the fitting
In addition to being securely clamped, what is an additional requirement for installing metal fuel, oil and hydraulic lines?
The lines must be electrically grounding to the structure
What are some of the most important advantages of TEFLON tubing?
- compatible with most fluids
- Wide temperature range
- Low resistance to fluid flow
- Long shelf and service life
Describe the operation of quick disconnect couplings:
Each half has a valve that is held open when coupled and is spring loaded closed when disconnected
Why are quick disconnect fittings used?
Quick means to connect or disconnect a fluid line without loss of fluid and entrance of air into the system
When fabricating a flexible hose what percent of the total length must be allowed for freedom of movement under pressure?
5 to 8% of its total length
How can you tell that a flexible hose has been installed in a twisted position?
A twisted lay line
Name at least two considerations when installing flexible, hose assemblies
- Slack
- Flexing
- Twisting
- Bending
- Clearance
- clamping
Scratches and nicks may be repaired IF they are less than what percentage of the wall thickness?
10%
Flexible hoses should be clamped every how many inches at least?
24
What is the difference between flare angles for aviation and automotive flares?
45° flares are used on cars
35° to 37° are used in aviation
Which steel alloy is noted for its toughness and is most commonly used for aircraft structures, frame members, engine mounts, landing gear, parts, and other structural parts?
Chrome Molybdenum steel
What type of cable is commonly used in primary control systems?
Extra flexible 7 x 19 stainless steel cable
