Pipes And Unions

Question 1

What are aircraft fluid lines usually made of?

Answer 1

Metal tubing or flexible hose

Question 2

Three parts of a pipe?

Answer 2

Two end fillings

Tube

Question 3

What are the dimensions of a pipe determined by?

Answer 3

External diameter

Wall thickness

Question 4

What is high pressure in rigid and flexible pipes?

Answer 4

Anything over 1500PSI

Question 5

What is medium pressure in rigid or flexible pipes?

Answer 5

Anything under 1500PSI

Question 6

What is low pressure in rigid or flexible pipes?

Answer 6

Suction and Return lines

Question 7

How are pipes identified?

Answer 7

Stencilled or stamped with drawing number or part number
Inspection stamp
Test stamp
Date of manufacture

Question 8

What is a pipe pressure-tested to?

Answer 8

1 to 1.5 times the normal working pressure

Question 9

What are the two types of identification?

Answer 9

Colour/symbol

Code (based on ATA100 numbering system)

Question 10

What does grey with triangles mean?

Answer 10

De-icing

Question 11

What does orange and blue with diamonds mean?

Answer 11

Instrument Air

Question 12

What does blue and yellow with circles mean?

Answer 12

Hydraulic

Question 13

What does yellow with squares mean?

Answer 13

Lubrication

Question 14

What colour means physically dangerous?

Answer 14

Grey - PHDAN

Question 15

Two categories of pipe fittings?

Answer 15

Flareless

Flared

Question 16

What is MS fitting?

What must you never do?

Answer 16

Ball-bush. Sleeve of malleable steel shaped by pre-stressing in a way that it’s cutting edge is pushed over the pipe, sealing it.

Never re-tighten

Question 17

What is another ball-bush fitting?

Answer 17

Harrison fitting

Question 18

What is a Harrison fitting?

Answer 18

Pipe swaged in the sleeve to form a tight seal. Special tool moulds sleeve and widens pipe. Suited for thin walled tubes.

Question 19

What is a Permaswage fitting?

Answer 19

For damaged pipes. Sleeve squeezed on using hyd-driven tool. Only for emergencies e.g military

Question 20

Advantages of a Harrison fitting?

Answer 20

Easy handling
Simple tooling
Vibration resistant

Question 21

Advantages of Permaswage fitting?

Disadvantages?

Answer 21

Quick, light, gives a good seal

Cannot be separated

Question 22

Two types of flared fittings?

Answer 22

Single flare

Double flare

Question 23

What is a Single Flared Fitting?

Answer 23

Special tool used to make flare, flare seals against cone.
Clear surfaces paramount
Do not overtighten
If a leak is found, dismantle and inspect

Question 24

What is the flare angle on aircraft?

Answer 24

37 degrees

Question 25

What is a Double Flared Fitting?

Answer 25

Soft aluminium tubing outside diameter 3/8” or smaller. Smoother and more concentric, gives a better seal, more durable

Question 26

What is Sharp-Bottomed pipe damage?

Answer 26

Loss of material damage cuts into material to form scratches

Question 27

What is Round-Bottomed pipe damage?

Answer 27

Loss of material damage at bottom is not sharp edged but rounded (abrasion)

Question 28

What is Round-Bottomed Impact pipe damage?

Answer 28

Dent in pipe walling

Question 29

What requirements must hoses meet?

Answer 29

Slack (2-4% length increase under pressure) | Must never be twisted

Question 30

Where/what are hoses used?

Answer 30

Connect stationary to dynamic | In high vibration areas

Question 31

What is low pressure in a hose?

Answer 31

Up to 600PSI

Question 32

What is medium pressure in a hose?

Answer 32

Up to 3000PSI

Question 33

What is high pressure in a hose?

Answer 33

3000PSI+

Question 34

What are Lay Lines?

Answer 34

Run along length of hose with twist indicator. Yellow, red, or white stripes incorporate data/information

Question 35

What is inspected for on hoses?

Answer 35

Deterioration Leaks Mechanical damage (rubbing)

Question 36

What must inner layers of a hose be?

Answer 36

``` Chemically compatible Neoprene - petroleum based fluid Buna N - petroleum based fluid Butyl - hydraulic fluid Teflon - almost all fluids ```

Question 37

What does hose reinforcement include?

Answer 37

Protective outer cover (physical/heat) Rubber impregnated fabric Stainless steel braid

Question 38

What angle is AN? Colour?

Answer 38

37 degrees Blue or black

Question 39

What angle is AC? Colour?

Answer 39

35 degrees Grey or yellow

Question 40

What is the only reusable hose fitting called?

Answer 40

Aeroquip

Question 41

What to inspect and check on a hose?

Answer 41

Inspect: applicability, length, cleanliness, damage Check: part number, cure and assembly dates

Question 42

What must a hose be?

Answer 42

Supported every 24 inches (2 ft) | Never twisted

Question 43

What fitting can replace a bending pipe?

Answer 43

Elbow fitting

Question 44

What is an Elbow Fitting?

Answer 44

Largest bend radius preferred. Protective sleeves - heat shrink, nylon spiral wrap, Teflon.

Question 45

What do some early products contain?

Answer 45

Asbestos

Question 46

What materials are used for a hydraulic fitting?

Answer 46

Aluminium allly (D) Cadmium plated steel CRES

Question 47

Advantages of fuel/hydraulic fittings?

Answer 47

Easy connection Speed Less fuel vapour Less hazard

Question 48

Types of fuel/hydraulic fittings?

Answer 48

``` Screw Insomatic push/pull Quick thread indicator Full grip push/pull Straight flow ball valve Ball-lock ```

Question 49

What does yellow with squares mean?

Answer 49

Lubrication

Question 50

What does red with stars mean?

Answer 50

Fuel

Question 51

What does red and grey with arrows mean?

Answer 51

Water injection

Question 52

What does orange with lightning mean?

Answer 52

Electrical conduit

Question 53

What does grey and brown with dots mean?

Answer 53

Air condition

Question 54

What does blue with waves mean?

Answer 54

Coolant

Question 55

What does green and rectangles mean?

Answer 55

Breathing oxygen

Question 56

What does brown with diamonds mean?

Answer 56

Fire protection