Fluid lines and fitting Flashcards
What are aircraft plumbing lines usually made of
Metal tubing or flexible hose and fittings
How is metal tubing sized
By outside diameter and wall thickness. Outside diameter is measured fractionally in sixteenths of an inch
What material should be selected for high pressure rigid fuel lines
Annealed or 1/4 hard corrosion resistant steal
What type of material should fittings be made of when used in stainless steel tubing
Stainless steel
What percent of flattening is allowed when bending metal tubing
25% max
What precautions should be taken when routing fluid lines adjacent to electrical wiring
Route the Fluid lines below the electrical wiring and maintain clearance of at least sixteenths of an inch whenever possible and in no case should fluid lines and electrical wiring be closer than 1/2 inch. Ensure that both wiring and fluid lines are fastened to the aircraft structure by clamps or other methods that will maintain the separation
What is the purpose of the identification strip running along the length of the flexible hose
Delay line and indicates if the hose has twisted during installation. There is no allowable twist
What are some synthetic material commonly used to manufacture flexible hose
Buns-N, neoprene, butyl, ethylene propylene diene rubber, And Teflon
How are standard AN type and AC Type fluid line fittings identified
AN fluid line fittings are colored either blue or black. While AC type fittings are usually gray and yellow.
AN fittings have courser threadsAnd they have a small shoulder between the threads and the 37° flare cone. The AC fittings are completely threaded all the way to the 35° flare cone
What is the purpose of using quick disconnect couplings in Fluid systems
They provide means of quickly disconnecting a line without a loss of fluid or air entering the system.
Quick disconnect couplings are installed at locations where frequent uncoupling of the line is required for inspection and maintenance. Each half has a valve that is open when coupled together and spring loaded to close when disconnected
How is a flexible hose sized
By the inside diameter in sixteenths of an inch increments
How much slack must be left in a flexible hose during installation
5 to 8% of the total hose length must be allowed for freedom of movement under pressure
How often should flexible hose be clamped in place
Every 24 inches
Name considerations when installing flexible hose assembly’s
Slack, flexing, twisting, bending, clearance, and clamps
What pressure is used to prove test a flexible hose assembly
1.5 times the recommended operating pressure of the hose
What are three parts of a military standard tube Fitting
Body, sleeve, nut
What will be the result of over tightening of flared tube Fitting
The compression sleeve cutting edge will cut too deep into the tube and cause the tube to be weekend, flareless fittings are made up of the tube, compression sleeve, and nut
What are the two kinds Of flares used in aircraft plumbing systems
Single flare and double flare
What is the difference between Automotive in aviation flares
Aviation flares should be 37° in automotive are 45°
What is the advantage of flexible Teflon hose over rubber hose
Teflon hose have better resistance to chemicals and a higher strength property at higher temperatures
What precautions should be taken when deburring and inspecting the flared end of the tube
Can you should be taken that the tube is not cracked or that the wall thickness is not reduced by the deburring process
What type of rubber is used in flexible lines that Carrie phosphate Esther Hydraulic fluid
Synthetic
What type of information is on a hose lay line
Information found on the lay line will indicate the type of hose, and the quarter and year of manufacture
