3.1.1 Piping systems are to be arranged so that supply of services relating to
the Ship Type will continue to be available in the event of a single failure or damage
of a system or item of equipment.
3.1.2 The
design of piping systems is to minimise vulnerability and provide
capability for maximising recovery of supply to users. Factors to
be considered include: redundancy, separation, protection, accessibility
for repair, means of bridging breaches, number of pumps, alternate
power supplies and use of portable pumps where appropriate.
3.1.4 The arrangement of equipment and systems is to ensure that failure or damage
to a system will not cause immediate complete loss of the system. Systems are to be
capable of accommodating progressive actions (manual and/or automatic) that will provide
availability of supply to Mobility and/or Ship Type systems for agreed periods of time
in the event of action damage.
3.1.5 In the
event of multiple failure or damage to a piping system, arrangements
are to be provided to enable the system to be reconfigured to supply
essential services.
3.1.6 Accessible
means of isolation are to be provided to isolate damaged areas to
ensure that maximum system capability remains available after damage
to the piping system.
3.1.7 Piping
systems are in general to be capable of providing support to, or substituting
for, a similar but damaged system.
3.1.8 Where
a piping system has failed or been damaged, any resulting hazards
are to be minimised.
3.1.9 All
equipment fitted in piping systems is to be readily accessible to
facilitate maintenance and survey. For this purpose, valves or cocks
are to be interposed between items of equipment and the inlet and
outlet pipes in order that any item of equipment may be shut off for
opening up and overhauling.
3.1.10 Filter
elements fitted in piping systems are to be capable of being cleaned
and or changed without interruption of fluid flow. Filter elements
fitted in refrigerant circuits are also to be arranged to minimise
refrigerant leakage to atmosphere when being cleaned and/or changed.
The arrangements for cleaning and changing filter elements are to
include means of isolation and recovery of ozone depleting substances
before opening up.
3.1.11 Pressure
relief devices are to be mounted in such a way that it is not possible
to isolate them from the part of the system which they are protecting
except that, where duplicated, a changeover valve may be fitted that
will allow either device to be isolated for maintenance purposes without
it being possible to shut off the other device at the same time. Where
arrangements are such that a relief valve can be removed from a common
discharge line shared with another relief valve, provision is to be
made to blank off the open connection to the discharge line, without
compromising the safety of the system.
3.1.12 Relief
discharge is to be led to a safe place. Discharge piping is to be
designed to preclude ingress of water, dirt or debris that may cause
the equipment to malfunction. Any common discharge system for relief
valves is to be arranged to ensure that with all the relief valves
open, the back pressure of the discharge system will not exceed 10%
of the valve set pressure.
3.1.14 Piping
system arrangements and associated equipment are to be capable of
operating satisfactorily under the conditions shown in Table 3.4.2 Inclinations in Pt 1, Ch 3.