Reg. 10.2.1.4.1:
Isolating
valves to separate the section of the fire main within the machinery space
containing the main fire pump or pumps from the rest of the fire main shall be
fitted in an easily accessible and tenable position outside the machinery
spaces. The fire main shall be so arranged that when the isolating valves are
shut all the hydrants on the ship, except those in the machinery space referred
to above, can be supplied with water by another fire pump or an emergency fire
pump. The emergency fire pump, its seawater inlet, and suction and delivery
pipes and isolating valves shall be located outside the machinery space. If
this arrangement cannot be made, the sea-chest may be fitted in the machinery
space if the valve (sea inlet valve) is remotely controlled from a position in the same
compartment as the emergency fire pump and the suction pipe is as short as
practicable. Short lengths of suction or discharge piping may penetrate the
machinery space, provided they are enclosed in a substantial steel casing, or
are insulated to "A-60" class standards. The pipes shall have
substantial wall thickness, but in no case less than 11 mm, and shall be welded
except for the flanged connection to the sea inlet valve.
A.- When suction and Discharge piping penetrate E/R spaces, the pipe shall be protected by steel casing or shall be insulated to A-60 class, there fore the basic fire-resisting ability of the pipe shall remain intact during a period of 60 minutes. It is not necessary to insulate distance pieces, sea inlet valve and sea-chest. The discharge piping it is conclude to be the pipe running from the emergency fire pump discharge to the isolating valve.
B.- The most common method to insulate a pipe to A-60 standard can be by covering and/or protecting the pipe with a steel faced mineral wool, which is approved as part of A-60 class division in accordance with the Fire Test Procedure Code.
C.- When sea inlet valve is inside E/R, this valve should not be fail close type in case the medium that move the valve actuator fail, instead fail open valve shall be use when remotely controlled. In my opinion this can be voided if the valve is opened/closed by a mecanical mean like a cardan joint intead control piping, actuacting devices and/or electric cables.
D.- In cases where main fire pumps are provided in compartments out side machinery spaces and where emergency fire pumps suction or discharge piping penetrate such spaces, above will be applied to the piping.
B.- The most common method to insulate a pipe to A-60 standard can be by covering and/or protecting the pipe with a steel faced mineral wool, which is approved as part of A-60 class division in accordance with the Fire Test Procedure Code.
C.- When sea inlet valve is inside E/R, this valve should not be fail close type in case the medium that move the valve actuator fail, instead fail open valve shall be use when remotely controlled. In my opinion this can be voided if the valve is opened/closed by a mecanical mean like a cardan joint intead control piping, actuacting devices and/or electric cables.
D.- In cases where main fire pumps are provided in compartments out side machinery spaces and where emergency fire pumps suction or discharge piping penetrate such spaces, above will be applied to the piping.
