Chapter 10 - Fluid Lines and Fittings - Oral Questions Flashcards Preview

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Flashcards in Chapter 10 - Fluid Lines and Fittings - Oral Questions Deck (20):

What are the two types of fluid lines 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 1/16 inch increments


When installing stainless steel tubing, what types 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

Single and double flare

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How can you determine if a fitting is an AN type rather than AC type

AN fittings have a shoulder between the flare cone and the end of the threads, AC don't.

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What are the most significant differences between AN and AC fittings?

Sleeve length,

thread pitch, and

the shoulder between the threads and flare cone on AN fittings

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What are the names of the parts of a flare-less tube fitting

The nut and the ferrule or sleeve

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How do you tell a flare-less fitting from a flare type fitting?

Flare-less 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?

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

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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

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How are flexible hose sizes designated?

By the inside diameter, measured in 1/16 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


Describe the operation of quick disconnect couplings

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Each half has a valve that is held open when coupled and is spring-loaded closed when disconnected


If you fabricate a replacement for a flexible hose, what percentage of the total length must be added to allow for movement under pressure?

5 to 8 percent


What happens to the tube when a flare-less fitting is overtightened?

The tube is weakened when the nut drives the cutting edge of the sleeve too deeply into the tube


Why are quick disconnect fittings used?

To provide a quick means to connect or disconnect a fluid line without loss of fluid or entrance of contaminants into system

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