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
ships 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 or cargo holds
for conveying fuel oil, lubricating oil or other flammable liquids,
or for bilge suction pipework within machinery spaces.
10.1.4 Aluminium
alloy pipes are not acceptable for fire extinguishing pipes unless
they are suitably protected against the effect of heat.
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.