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22 Cards in this Set
- Front
- Back
What are the two types of fluid lines found in aircraft? |
Rigid metal lines and flexible hoses |
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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 |
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When installing stainless steel tubing, what types of fittings should be used? |
Stainless steel fittings |
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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 |
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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 |
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What is the effect of over tightening a flare type fitting |
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? |
The lines must be electrically bonded to the structure |
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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 |
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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 |
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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 |
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Describe the operation of quick disconnect couplings |
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? |
5 to 8 percent |
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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 |
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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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What precautions should be observed when installing fittings or connecting aluminum alloy lines? |
Identify flared tube fittings, dissimilar metal, and cross threading |
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When should grommets be used in tubing installation? |
Anytime the tubing passes through an opening in the aircraft structure |