D- fluid lines and fittings Flashcards
What two general types of fluid lines are commonly used in aircraft plumbing
Metal tubing and flexible hose
how is metal tubing classified in size?
Metal tubing is sized by outside diameter in 1/16 inch increments and wall thickness
what are the identification markings usually found on flexible rubber hose
hose size, manufacturer, date of manufacturer, pressure, and temperature limits
what caution must be observed when deburring the end of tubing after cutting
Extreme care that the wall thickness is not fractured or reduced in size
What are the parts of a military standard flareless tube fitting?
A body, a sleeve, and a nut
what are the two kinds of flareless generally used in aircraft plumbing system?
Single flare, and double flare
what is the principal advantage of flexible Teflon hose?
High operating strength at elevated temperatures
how can you tell that your flexible hose has been installed in a twisted position?
By the identification strip running along the hose length
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
What happens to a flareless tube fitting when it is overtightened
Nut drives the cutting edge of the sleeve, causing the tube to be weaken
what type of fitting should be used with stainless steel tubing?
Stainless steel fittings
in addition to being securely clamped in place, how should metal,fuel,oil, and hydraulic lines be installed in an aircraft?
They should be electrically connected
what is the putpose of a sleeve on a flared-tube connection?
The nut fits over the sleeve and when tightened, draws the sleeve and tubing flare tightly against the male fitting form the seal
when inspecting fittings, how may flare less fittings be distinguished from a flared tube type?
there is no flare cone and no space between the threads and the end of the fitting
how is flared tubing affected by over tightening of the fittings?
The tube flare is likely to be damaged, forming a weak point which may fail when under pressure
what percentage of flattening is allowed when bending metal tubing?
do not exceed 75% of original diameter
scratches and nicks may be repaired if they are less than what percent of the wall thickness?
10 percent
flexible hose should be clamped at least every how many inches?
24 inches
what is the difference between flare angles for aviation and automotive flares?
Aviation is 37 degrees. automotive is 45 degrees
name at least two synthetic materials commonly used in the manufacture of flexible hoses
neoprene and buna-N
what is the maximum interval for repeating the required markings on a flexible hose?
Not more than nine inches long the length of the hose
When selecting a flexible hose for use in a phosphate ester based hydraulic fluid (skydrol) system, the hose should be made of which synthetic rubber compound?
Butyl
Name at least two considerations when installing flexible hose assemblies?
Slack, flexing, twisting, bending, clearance, and clamps
