8.12.1 Overboard discharges and valve connections
a) Overboard discharges are to have pipe spigots extending
through the shell plate and welded to it, and are to
be provided at the internal end with a flange for connection
to the valve or pipe flange.
b) Valves may also be connected to the hull plating in
accordance with the provisions of [2.8.3], item c).