4.1.1 Spheroidal
or nodular graphite iron may be accepted for bilge, ballast and cargo
oil piping.
4.1.2 Spheroidal
or nodular graphite iron castings for pipes, valves and fittings in
Class II and Class III piping systems are to be made in a grade having
a specified minimum elongation not less than 12 per cent on a gauge
length of 5,65 
, where S
o is the actual cross-sectional
area of the test piece.
4.1.3 Castings
for Class II systems, also for ship-side valves and fittings and valves
on the collision bulkhead, are to be manufactured and tested in accordance
with the requirements of Ch 7 Iron Castings of
the Rules for Materials.
4.1.4 Castings
for Class III systems are to comply with the requirements of acceptable
national specifications. A manufacturer’s certificate will be
accepted and is to be provided for each consignment of material for
Class III systems, see also
Pt 5, Ch 12, 1.7 Materials and Ch 1, 3.1 General 3.1.3.(c) of
the Rules for Materials.
4.1.5 Proposals
for the use of this material in Class I piping systems will be specially
considered, but in no case is the material to be used in systems where
the design temperature exceeds 350°C.