Rigid Fluid Lines

Question 1

AN fittings have a ______ Connection?

Answer 1

Flared Connection

Question 2

What degree are AN flared fittings?

Answer 2

37 Degrees

Question 3

What degree are AC flared fittings?

Answer 3

35 Degrees

Question 4

What degree are MS flared fittings?

Answer 4

MS fittings do not have flares

Question 5

When was copper tubing used extensively in aircraft?

Answer 5

During the early days of aviation

Question 6

How does copper become hard and brittle in aircraft?

Answer 6

Vibration

Question 7

How do we restore properties in copper?

Answer 7

Annealing

Question 8

Aluminum allow tubing is used for?

Answer 8

General purpose lines of low or medium fluid pressures such as hydraulic and pneumatic. 1000 PSI - 1500 PSI

Question 9

What is CRES?

Answer 9

Corrosion resistant steel tubing

Question 10

Where are steel lines mainly used?

Answer 10

In areas where there is high risk of foreign object damage (FOD) such as the landing gear and wheel well areas.

Question 11

Where are titanium lines used?

Answer 11

They are used extensively in transport and high performance aircraft and around engines.

Question 12

True or false: Titanium is 50 percent stronger then steel and 30 percent lighter then steel.

Answer 12

False! Titanium is 30 percent stronger then steel and 50 percent lighter then steel.

Question 13

How do we positively identify the material used in the original line installation?

Answer 13

Compare code markings on replacement tubing.

Question 14

On large aluminum alloy tubing the alloy designation can be found where?

Answer 14

Stamped on the surface.

Question 15

On small aluminum tubing the alloy designation maybe __________; but more often is shown by a __________

Answer 15

MAYBE stamped on the surface, Color code

Question 16

How do we size rigid tubing lines?

Answer 16

By the outside diameter and wall thickness

Question 17

OD tubing is sized in what increments?

Answer 17

1/16 inch

Question 18

A #6 rigid tube is what size?

Answer 18

6/16ths or 3/8ths

Question 19

Wall thickness is specified in what increment?

Answer 19

Thousandths of an inch

Question 20

How do we find the OD of a tube?

Answer 20

ID + 2 wall thickness

Question 21

How do we find the ID of a tube?

Answer 21

OD - 2 wall thickness

Question 22

How do we find total wall thickness?

Answer 22

OD - ID

Question 23

How do we find 1 wall thickness?

Answer 23

OD - ID divided by 2

Question 24

Replacement tubing should be what?

Answer 24

The same sized material as the original line or approved substitute.

Question 25

How do we ID the material if there are no markings?

Answer 25

Hardness, Acid and Magnetic testing methods

Question 26

Fabrication of tube assemblies consists of what?

Answer 26

Cutting, deburring, bending and tube joint preparation

Question 27

How do we cut rigid tubing?

Answer 27

Roll cutters or Fine tooth hacksaw with 32 teeth per inch.

Question 28

When you cut tubing you should always cut ______ for bending variations.

Answer 28

10% extra material

Question 29

What is the objective of cutting rigid tubing?

Answer 29

To produce a square end free from burrs.

Question 30

How do we deburr a tube?

Answer 30

Deburring tool

Question 31

The objective of tube bending is to obtain what?

Answer 31

A smooth bend without flattening the tube.

Question 32

Tubing under _____ inch diameter can be bent without the use of a bending tool.

Answer 32

1/4

Question 33

A small amount of flattening in bends is acceptable but must not be less then ______ percent of the original OD

Answer 33

75%

Question 34

Fittings for tube connections are made of what materials?

Answer 34

Aluminum alloy, titanium, corrosion resistant steel and brass and bronze

Question 35

What are the 5 classifications of tube fittings?

Answer 35

Flared, Flareless, Swaged, Beaded, brazed and welded

Question 36

The two major tube joint fittings are the _______ and ______.

Answer 36

Flared and Flareless

Question 37

What are the benefits of a double flare over a single flare?

Answer 37

A double flare seals better and is more resistant to the shearing effect of torque.

Question 38

What tube size are double flares mostly used in?

Answer 38

3/8 and smaller

Question 39

Presetting is only required on what type of fitting?

Answer 39

MS fittings

Question 40

What does PHDAN stand for?

Answer 40

Physically Dangerous

Question 41

What lines are marked as PHDAN?

Answer 41

Lines with oxygen, nitrogen or Freon

Question 42

What color code and symbol is a fuel line?

Answer 42

Red with Diamonds

Question 43

What color code and symbol is water injection?

Answer 43

Red and Grey with chevrons pointing down

Question 44

What color code and symbol is electrical conduit?

Answer 44

Orange with lightning bolts

Question 45

What color code and symbol is compressed gas?

Answer 45

Orange with diagonal rectangles

Question 46

What color code and symbol is instrument air?

Answer 46

Orange and blue with crisscrossing lines

Question 47

What color code and symbol is coolant?

Answer 47

Blue with wavy rectangles

Question 48

What color code and symbol are hydraulic lines?

Answer 48

Blue and yellow with circles

Question 49

What color code and symbol are lubrication lines?

Answer 49

Yellow with squares

Question 50

What color code and symbol is breathing oxygen?

Answer 50

Green with rectangles

Question 51

What color code and symbol is Deicing?

Answer 51

Grey with triangles

Question 52

What color code and symbol is fire protection?

Answer 52

Brown with squared diamonds

Question 53

What color code and symbol is air conditioning?

Answer 53

Brown and grey with random sized circles

Question 54

What is the warning symbol?

Answer 54

white background with black skull and bones

Question 55

List the 5 fluid line end fittings?

Answer 55

Universal bulkhead fittings, AN flared, MS flareless, swaged fittings and AC fittings

Question 56

What color are aluminum alloy fittings?

Answer 56

Blue

Question 57

What color are carbon steel fittings?

Answer 57

Black

Question 58

What color are CRES fittings?

Answer 58

Natural

Question 59

What color are Aluminum-bronze fittings?

Answer 59

Cadmium plate (goldish)

Question 60

What color are titanium fittings?

Answer 60

Natural to grey

Question 61

Describe Cryofit fittings.

Answer 61

The sleeve is manufactured 3% smaller, frozen in liquid nitrogen and expanded 5% larger than the line. Sleeve is removed from the liquid nitrogen and inserted on to the tube where the sleeve contracts to its original 3% smaller size and creates a permanent seal.

Question 62

What color are AC fittings?

Answer 62

Grey or yellow

Question 63

What is the difference between a AN fitting and a AC fittings?

Answer 63

AN fittings have 37 degree flares and AC fittings have 35 degree flares and are slightly longer.

Question 64

The liquid medium for proof testing tube assemblies should be what?

Answer 64

Hydraulic fluid, water or oil

Question 65

What should oxygen tubing be proof tested with?

Answer 65

Dry nitrogen

Question 66

True or False: You should always apply a compound to the faces of the fitting or flare.

Answer 66

FALSE. You should never apply any compound as it will destroy the metal on metal contact between the fitting and flare.

Question 67

If an AN flared tube assembly leaks after being tightened to the proper torque what steps do you take next?

Answer 67

Disassemble the line for repair or replace the line completely

Question 68

What can be done if a flareless tube assembly leaks?

Answer 68

It can be tightened 1/16th turn beyond the noted torque

Question 69

Leakage of a flared tube assembly is usually caused by what?

Answer 69

Flare distortion in the nut threads, sleeve cracked, flared out of roundness, flare is cracked or split

Question 70

Tubing that has nicks scratches or dents are acceptable if the dent has a depth of what?

Answer 70

Less than 20% of the tubing diameter unless its in the heel of a short bend radius

Question 71

A nick or scratch of that has a depth of less then _____ of the wall thickness on aluminum or steel should be reworked before it is acceptable.

Answer 71

10%