General Chapter 10 Flashcards
Fluid Lines and Fittings
What are the two types of fluid lines commonly found in aircraft?
Rigid metal lines and flexible hoses.
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 the seal.
Describe the two types of flares commonly used on aircraft tubing.
The single flare and the 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 MiI 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 hose sizes designated?
By the inside diameter, measured in 1/16th inch increments.