7.9

Question 1

Pipe cutting

Answer 1

A pipe cutter is used.
A hacksaw with a fine tooth (32tpi) can be used.
Always cut longer than required length by 10 % to allow for variations when bending.
Must be deburred

Question 2

Bending pipes

Answer 2

Lightly lubricate pipe at bend point.
Use offset bend calculators.
A small amount of flattening is acceptable, not less then 75% original diameter though.
Pipes with wrinkling, kinking, excessive flattening must not be installed.

Question 3

Flaring pipes

Answer 3

Double flare - 3/8 inch pipe or less.

37 degrees

Question 4

Belling pipes

Answer 4

Lines carrying low presssure fluids or air can be connected to rubber hoses by belling the end.
Held with a screw clamp.
Pipes with an OD of 1/4 in can be belled using a hand belling tool.
Over this needs a power belling machine.

Question 5

Permissible repairs of pipes

Answer 5

Repairs to engine pipes are not permitted.
Aluminium alloy repairable by CRES or titanium alloy.
CRES repairable by titanium except in the pylon
Titanium replaceable by CRES.
Scratches or nicks not deeper then 10%
A dent of less then 20% except in a heel of a bend.
Damages for hard or thin walled are considerable less then aluminium piping

Question 6

Cleaning a pressure testing of hoses

Answer 6

Cleaned with compresses air internally from both directions.
Proof tested generally to 1.5 x working pressure by capping one end.
Performed by qualified personnel and a certificate of testing is issued.

Question 7

How often are hoses supported

Answer 7

Every 60cm