10.1.1 The
use of aluminium alloy material in Class III piping systems will be
considered in relation to the fluid being conveyed and operating conditions
of temperature and pressure.
10.1.2 In general,
aluminium alloy may be used for air and sounding pipes for water tanks
and dry spaces providing it can be shown that pipe failure will not
cause a loss of integrity across watertight divisions. In craft of
aluminium construction, aluminium alloy may also be used for air and
sounding pipes for fuel oil, lubricating oil and other flammable liquid
tanks provided the pipes are suitably protected against the effects
of fire.
10.1.3 Aluminium
alloy pipes are not to be used in machinery spaces, ro-ro spaces,
special category spaces or cargo spaces for conveying fuel oil, lubricating
oil or other flammable liquids, or for bilge suction pipework within
such spaces.
10.1.4 Aluminium
alloy pipes are not acceptable for fire extinguishing pipes unless
they are suitably protected against the effect of heat. The use of
aluminium alloy with appropriate insulation will be considered when
it has been demonstrated that the arrangements provide equivalent
structural and integrity properties compared to steel. In open and
exposed locations, where the insulation material is likely to suffer
from mechanical damage, suitable protection is to be provided.
10.1.5 The
minimum thickness of aluminium alloy pipes is to be not less than
that shown in Table 1.10.1 Minimum thickness of aluminium
pipes.
Table 1.10.1 Minimum thickness of aluminium
pipes
| Nominal
pipe size (mm)
|
Minimum
wall thickness (mm)
|
| 10
|
1,7
|
| 15
|
2,1
|
| 20
|
2,1
|
| 25
|
2,8
|
| 40
|
2,8
|
| 50
|
2,8
|
| 80
|
3,0
|
| 100
|
3,0
|
| 150
|
3,4
|
| 200
|
3,8
|
| 250 and
over
|
4,2
|
10.1.6 Design
requirements for aluminium pressure pipes for design pressures greater
than 7 bar will be specially considered.
10.1.7 Attention
is drawn to the susceptibility of aluminium to corrosion in the region
of welded connections.