General Ch 10 Fluid Lines and Fittings – Flashcards
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Define complimentary action
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two actions that create the same result
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What are the two types of fluid lines commonly found in aircraft?
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Rigid metal lines and flexible hoses.
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Describe the method of classifying metal tube according to size.
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Metal tubing is sized according to wall thickness and outside diameter. Outside diameter is measured in 1/16th inch increments.
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When installing stainless steel tubing, what type of fittings should be used?
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Stainless steel fittings.
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What is the function of the sleeve on a flared-tube fitting?
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The nut fits over the sleeve and draws the sleeve and the tubing flare tightly against the male fitting to form the seal.
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Describe the two types of flare commonly used on aircraft tubing.
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The single flare and the double flare.
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How can you determine if a fitting is an AN type rather than an AC type?
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AN fittings have shoulder between the flare cone and the end of the threads, AC fittings do not.
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What are the most significant differences between AN and AC fittings?
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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 flareless tube fitting?
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The nut and the ferrule or sleeve.
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How do you tell a flareless fitting from a flare-type fitting?
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Flareless fittings don't have a flare cone and there is no space between the threads and the end of the fitting.
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What is the effect of over-tightening a flare type fitting?
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The sealing surface may be damaged or the flare cut off.
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In addition to being securely clamped, what is an additional requirement for installing metal fuel, oil and hydraulic lines?
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The lines must be electrically bonded to the structure.
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What are some of the important advantages of Teflon tubing?
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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.
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Describe the identification markings commonly found on flexible hoses.
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A lay line, identification such as 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?
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The lay line will be straight if the hose is properly installed. A twisted lay line indicated an incorrect installation.
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How are flexible hose sizes designated?
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By the inside diameter, measured in 1/16th inch increments.
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What precautions must be observed when deburring the need of a tube after it is cut?
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The wall thickness must not be reduced in size or fractured.
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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.
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If you fabricate a replacement for a flexible hose, what percentage of the total length must be added to allow for movement under pressure?
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5 to 8 percent
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What happen to the tube when a flareless fitting is overtightened?
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The tube is weakened when the nut drives the cutting edge of the sleeve too deeply into the tube.
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Why are quick disconnect fittings used?
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To provide a quick means to connect or disconnect a fluid line without loss f fluid or entrance of air into the system.
