Fluid Lines and Fittings Flashcards
Describe the method of classifying metal tube according to size.
Metal tubing is sized according to wall thickness and outside diameter. Outside diameter is measured in 1/16th-inch increments.
When installing stainless steel tubing, what type of fittings should be used?
Stainless steel fittings
What is the function of the sleeve on a flared tube fitting?
The nut fits over the sleeve and draws the sleeve and the tubing flare tightly against the male fitting to form a seal.
Describe the two types of flares commonly used on aircraft tubing.
The single flare and double flare.
How can you determine if a fitting is an AN type rather than an AC type?
AN fittings have a shoulder between the flare cone and the end of the threads, AC fittings do not.
What are the most significant differences between AN and AC fittings?
Sleeve length, thread pitch, and the shoulder between the threads and the flare cone on AN fittings.
What are the names of the parts of a flareless tube fitting?
The nut and the ferrule or sleeve
How do you tell a flareless fitting 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.
What is the effect of over-tightening a flare type fitting?
The sealing surface may be damaged or the flare cut off.
In addition to being securely clamped, what is an additional requirement for installing metal fuel, oil, and hydraulic lines?
The lines must be electrically bonded to the structure.
What are some of the important advantages of Teflon tubing?
It is compatible with nearly every liquid, has a broad operating temperature range, low resistance to fluid flow and has a very long shelf and service life.
Describe the identification markings commonly found on flexible hoses.
A lay line, identification such as a Mil Spec number, the manufacturer’s name or symbol, the hose size, and a date code.
How can you determine if a flexible hose has been correctly or incorrectly installed?
The lay line will be straight if the hose is properly installed. A twisted lay line indicates an incorrect installation.
How are flexible hoses designated?
By the inside diameter, measured in 1/16th-inch increments.
What precautions must be observed when deburring the end of a tube after it is cut?
The wall thickness must not be reduced in size or fractured.
