Fluid lines and fittings Flashcards
(23 cards)
what two general types of fluid lines are commonly used in aircraft plumbing
metal tubing (rigid fluid lines) 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 manufacture, 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, sleeve and a nut
what are the two kinds of flares generally used in aircraft plumbing systems
the single flare and the double flare
what is the principle advantage of flexible Teflon hose
high operating strength at elevated temperatures
how can you tell that a flexible hose has been installed in a twisted position
by the identification stripe 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
from 5 to 8 percent of its total length
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 type of fittings (material) 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 (grounded to the aircraft structure)
what is the purpose 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 to form the seal
when inspecting fittings, how may a flareless fitting be distinguished from a flare 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 percent of original diameter
scratches and nicks may be repaired if they are less than what percent of the wall thickness
10 percent
flexible hoses 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
Buna-N, Neoprene, Butyl, Ethylene Propylene Diene Rubbber (EPDM) and Teflon
what is the maximum interval for repeating the required markings on a flexible hose
not more than nine inches along 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
