41 Questions
What is the color code for fluid lines carrying fuel?
red
A 3/8 inch aircraft high pressure flexible hose as compared to 3/8 inch metal tubing used in the same system will
have equivalent flow characteristics.
What is the advantage of a double flare on aluminum tubing?
More resistant to damage when the joint is tightened.
When presetting flareless fittings on 3/8 inch aluminum alloy tubing, the nut should be turned ______ turn(s) after the ferrule is tight against the presetting tube.
1 to 1-1/6
Which statement is true regarding the variety of symbols utilized on the identifying color-code bands that are currently used on aircraft plumbing lines?
Symbols are always black against a white background regardless of line content.
Excessive stress on fluid or pneumatic metal tubing caused by expansion and contraction due to temperature changes can best be avoided by
providing bends in the tubing.
From the following sequences of steps, indicate the proper order you would use to make a single flare on a piece of tubing:
- Place the tube in the proper size hold in the flaring block.
- Project the end of the tube slightly from the top of the flaring tool, about the thickness of a dime.
- Slip the fitting nut and sleeve on the tube.
- Strike the plunger several light blows with a lightweight hammer or mallet and turn the plunger one-half turn after each blow.
- Tighten the clamp bar securely to prevent slippage.
- Center the plunger or flaring pin over the tube.
3, 1, 6, 2, 5, 4.
Which tubings have the characteristics (high strength, abrasion resistance) necessary for use in a high-pressure (3,000 PSI) hydraulic system for operation of landing gear and flaps
CRES, annealed or 1/4H.
A scratch or nick in aluminum tubing can be repaired provided it does not
appear in the heel of a bend.
A certain amount of slack must be left in a flexible hose during installation because, when under pressure, it
expands in diameter and shortens in length.
45 degree flares are used for what kind of fittings?
Automotive
Metal tubing fluid lines are sized by wall thickness and
outside diameter in 1/16 inch increments.
The maximum distance between end fittings to which a straight hose assembly is to be connected is 50 inches. The minimum hose length to make such a connection should be
52-1/2 inches.
Which statement is true regarding flattening of tubing in bends?
Flattening by not more than 25 percent of the original diameter is permissible.
What is the color of an AN steel flared-tube fitting?
Black
The material specifications for a certain aircraft require that a replacement oil line be fabricated from 3/4-inch 0.072 5052-0 aluminum alloy tubing. What is the inside dimension of this tubing?
0.606 inch.
What is the color code for fluid lines carrying fire extinguishing agent?
Brown
In most aircraft hydraulic systems, two-piece tube connectors consisting of a sleeve and a nut are used when a tubing flare is required. The use of this type connector eliminates
the possibility of reducing the flare thickness by wiping or ironing during the tightening process.
What is an advantage of a double flare on aluminum tubing?
More resistant to damage when joint is tightened.
What is the color code for fluid lines carrying hydraulic fluid?
Blue/Yellow
When a Teflon hose has been in service for a time, what condition may have occurred and/or what precaution should be taken when it is temporarily removed from the aircraft?
The hose may have developed a set or been manufactured with a pre-set shape. It must be supported to maintain that shape.
Flexible lines must be installed with
5% - 8% slack
Scratches or nicks on the straight portion of aluminum alloy tubing may be repaired if they are no deeper than
10 percent of the wall thickness.
Hydraulic tubing, which is damaged in a localized area to such an extent that repair is necessary, may be repaired
by cutting out the damaged area and utilizing a swaged tube fitting to join the tube ends.
In metal tubing installations,
tension is undesirable because pressurization will cause it to expand and shift.
The term 'cold flow' is generally associated with
impressions left in natural or synthetic rubber hose material.
A certain amount of slack must be left in a flexible hose during installation because, when under pressure, it
contracts in length and expands in diameter.
The primary purpose of providing suitable bends in fluid and pneumatic metal tubing runs is to
prevent excessive stress on the tubing.
Which of the following statements is/are correct in reference to flare fittings?
- AN fittings have an identifying shoulder between the end of the threads and the flare cone.
- AC and AN fittings are considered identical except for material composition and identifying colors.
- AN fittings are generally interchangeable with AC fittings of compatible material composition.
1
Every tubing installation must have at least one bend to
prevent excess stress on the tubing
Which coupling nut should be selected for use with 1/2-inch aluminum oil lines which are to be assembled using flared tube ends and standard AN nuts, sleeves, and fittings?
AN-818-8.
Flexible lines must be installed with
a slack of 5 to 8 percent of the length.
Rolling-type Flaring Tools are used to flare X, X, and X tubing.
Soft copper, aluminum, brass.
Which of the following hose materials are compatible with phosphate-ester base hydraulic fluids?1. Butyl.2. Teflon.3. Buna-N.4. Neoprene
1 and 2.
To find the inside diameter of rigid tubing, twice the wall thickness must be subtracted from the _______ diameter.
outside
What is the maximum outside diameter of soft aluminum tubing that can be double-flared?
3/8 inch
If a flared tube coupling nut is overtightened, where is the tube most likely to be weakened/damaged
At the sleeve and flare junction.
High-pressure oxygen is typically carried in a stainless steel line.
true
Metal tubing fluid lines are sized by wall thickness and
outside diameter in 1/16 inch increments.
What process is necessary prior to installing new flareless fittings?
Presetting
When flaring aluminum tubing for use with AN fittings, the flare angle must be
37 deg
Test your knowledge of aircraft plumbing and tubing with this quiz covering topics such as color codes for fluid lines, advantages of double flare on aluminum tubing, and proper handling of flareless fittings. This quiz also includes questions on symbols used on identifying color-code bands and strategies for avoiding stress on metal tubing due to temperature changes.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
