7.9 Pipes And Hoses

Question 1

What is a tubes dimensions determined by?

Answer 1

External diameter, wall thickness

Question 2

What’s is the pressure of a high pressure line

Answer 2

Above 1500 psi

Question 3

What is the pressure of a medium pressure line?

Answer 3

Under 1500 psi

Question 4

What is a low pressure line?

Answer 4

Suction and return

Question 5

What can be used instead of hoses?

Answer 5

Flexible metal pipes

Question 6

What must be taken into account when installing tubes?

Answer 6

Vibration and movement

Question 7

How is a tube cleaned internally?

Answer 7

Pressurised air

Question 8

What are support clamps used for?

Answer 8

Securing tubes to the aircraft

Question 9

What are the two most common clamps?

Answer 9

Rubber cushioned clamp, plain clamp

Question 10

What is an advantage of rubber cushioned clamps?

Answer 10

Limit vibration

Question 11

What material should the cushion clamps use when around liquid?

Answer 11

Teflon

Question 12

What is a bonded clamp used for?

Answer 12

Securing hydraulic, fuel and oil lines

Question 13

How does a flareless tube fitting achieve its seal?

Answer 13

Ball bush principle

Question 14

What is an MS fitting?

Answer 14

Sleeve of malleable steel shaped over pipe

Question 15

What is a Harrison fitting?

Answer 15

Sleeve of solid steel which the tube seals onto from inside using swaging

Question 16

What is required for a flare type fitting?

Answer 16

Specialised tool

Question 17

Why are flare type fittings used in engines?

Answer 17

Low vibration

Question 18

What is the standard flare angle of flare type fittings?

Answer 18

37

Question 19

What are the 2 types of flare fitting?

Answer 19

Single, double

Question 20

What is the diameter of a double flare?

Answer 20

3/8 or smaller

Question 21

Why is a double flare better then single flare?

Answer 21

Better seal, resistant to shearing/torque

Question 22

What is a permaswage fitting?

Answer 22

Steel sleeve squeezed onto pipe using press

Question 23

What affects the tool you use when bending pipes?

Answer 23

Diameter

Question 24

When inspecting tubes and pipes what defects do you look for?

Answer 24

. Nicks
. Scratches
. Cracks
. Scores
. Bends
. Corrosion

Question 25

Why are hoses uses?

Answer 25

Flexible, withstand high vibration

Question 26

What is a low pressure in a hose?

Answer 26

Up to 600 psi

Question 27

What is a medium pressure in a hose?

Answer 27

Up to 3000 psi

Question 28

What is high pressure in a hose?

Answer 28

3000 plus psi

Question 29

What run along the length of the hose?

Answer 29

Lay lines

Question 30

What does a lay line indicate?

Answer 30

Twisting

Question 31

What do you inspect a hose for?

Answer 31

Length, cleanliness, damage

Question 32

What do you check a hose label for?

Answer 32

Part number, cure date, assembly date

Question 33

What should hoses be fitted with if they could bend or move?

Answer 33

Clamps

Question 34

What colour are lay lines

Answer 34

Yellow, red or white

Question 35

What’s are advantages of a pemerswage fitting

Answer 35

It can be made quickly in situ, light and gives a good steal

Question 36

What’s a disadvantage of a permerswage fitting

Answer 36

The fitting cannot be separated

Question 37

What are the two most common clamps used

Answer 37

Rubber cushioned clamp and plain clamp

Question 38

What do rubber cushioned clamps do

Answer 38

Secure lines which are subject to vibration

Question 39

Why do we used bonded clamps

Answer 39

Has an electrical lead secured to aircraft structural, bonding it. Contains, hydrolic oil or fuel

Question 40

What fitting does a Harrison fitting have

Answer 40

Ball bush fitting

Question 41

What are the two methods of making a single flare

Answer 41

Impact type - one with hammer Roller type - no hammer/ preferred one

Question 42

What is the difference between AN fitting and AC (name all An things for this one)

Answer 42

37 degrees Has a recess Coarser Blue/black Longer

Question 43

What is the difference between AN fitting and AC (name all ACthings for this one)

Answer 43

35 degrees No recess Finer Grey or yellow Shorter

Question 44

What is a swage/Harrison fitting suited too

Answer 44

Thin walled tubes as almost completely vibration resistant

Question 45

Why would you use a hose

Answer 45

to connect stationary to moving parts Or in high vibration areas

Question 46

When fitting a hose assembly it should be fitted every …..

Answer 46

24 inches

Question 47

What is recommended before commencing a bend using a hand tube bender

Answer 47

Lightly lubricate the bend point

Question 48

Why does a hose need to slack and what percentage is required

Answer 48

They reduce their length by 2-4% and expand when under pressure so 5-8% manufactured longer

Question 49

What system is used to protect hoses assemblies from chafing and temps

Answer 49

Protective sleeves - heat shrink - nylon spiral wrap - Teflon