3.1.1 All sea inlet and overboard discharge pipes are to be fitted with valves or
cocks secured direct to the shell plating, or to fabricated water boxes attached to the
shell plating. These fittings are to be secured by studs or by tap bolts screwed into
heavy pads welded to the plating. The stud or tap bolt holes are not to penetrate the
plating.
3.1.2 Alternatively,
distance pieces of short rigid construction and made of approved material
may be fitted between the valves and the shell plating. The thickness
of such pipes is to be equivalent to shell thickness. Distance pieces
of steel may be welded to steel shell plating and distance pieces
of aluminium alloy may be welded to aluminium alloy shell plating.
Details of the welded connections and of fabricated boxes are to be
submitted.
3.1.3 The arrangements
are to be such that the section of pipe immediately inboard of the
shell valve may be removed without affecting the watertight integrity
of the hull.
3.1.5 Shell
valves are to be manufactured from non-heat sensitive materials and
tested in accordance with the appropriate requirements of the Rules for the Manufacture, Testing and Certification of Materials, July 2022 (hereinafter referred to as the Rules for
Materials). Special consideration will be given to the use of other
materials on craft of aluminium or composite construction. Where the
valves are manufactured from spheroidal or nodular graphite cast iron
they are to be produced at a works approved by Clasifications Register (hereinafter
referred to as 'LR'). Grey cast iron is not acceptable.
3.1.6 Shell
valves are to be fitted in accessible positions and are to be capable
of being operated from positions which are readily accessible in case
of influx of water to the compartment.
3.1.7 Valve
hand wheels and cock handles are to be suitably retained on the spindles.
Means are to be provided to indicate whether the valve or cock is
open or closed.
3.1.8 The scantlings
of valves and valve stools fitted with steam or compressed air clearing
connections are to be suitable for the maximum pressure to which the
valves and stools may be subjected.