2.2 Requirements Applicable
to Piping Systems Depending on Service and/or Locations
2.2.1 Fire Endurance
2.2.1.1 General
Pipes and their associated fittings whose functions or integrity
are essential to the safety of ships are required to meet the minimum
fire endurance requirements given below.
2.2.1.2 Fire endurance requirements
The fire endurance of a piping system is the capability to maintain
its strength and integrity (i.e. capable of performing its intended function) for
some predetermined period of time, while exposed to fire that reflects anticipated
conditions, Three different levels of fire endurance for plastic are given. These
levels consider the different severity of consequences resulting from the loss of
system integrity for the various applications and locations. The highest fire
endurance standard (level 1) will ensure the integrity of the system during a full
scale hydrocarbon fire and is particularly applicable to systems where loss of
integrity may cause outflow of flammable liquids or spread of fire through duct
piping and worsen the fire situation. The intermediate fire endurance (level 2)
intends to ensure the availability of systems essential to the safe operation of
the ship, after a fire of short duration, allowing the system to be restored after
the fire has been extinguished. The lowest level (level 3) is considered to
provide the fire endurance necessary for a water filled piping system to survive a
local fire of short duration. The system's functions should be capable of being
restored, after the fire has been extinguished.
2.2.1.2.1
Level 1- piping system
essential to the safety of the ship and those systems outside machinery
spaces where the loss of integrity may cause outflow of flammable
fluid and worsen the fire situation should be designed to ensure a
fully developed hydrocarbon fire for a long duration without loss
of integrity under dry conditions. Piping having passed the fire endurance
test method specified in appendix 1 for a duration of a minimum of
one hour without loss of integrity in the dry condition is considered
to meet level 1 fire endurance standard.
Level 1W – Piping systems similar to level
1 systems except these systems do not carry flammable fluid or any
gas and a maximum 5% flow loss in the system after exposure is acceptablefootnote.
2.2.1.2.2
Level 2- piping systems
essential to the safe operation of the ship should be designed to
endure a fire without loss of the capability to restore the system
function after the fire has been extinguished. Piping having passed
the fire endurance test specified in appendix
1 for a duration of a minimum of 30 minutes in the dry condition
is considered to meet level 2 fire endurance standard.
Level 2W – Piping systems similar to level
2 systems except a maximum 5% flow loss in the system after exposure
is acceptablefootnote.
2.2.1.2.3
Level 3- piping systems
essential to the safe operation of the ship should be designed to
endure a fire without loss of the capability to restore the system
function after the fire has been extinguished. Piping having passed
the fire endurance test specified in appendix
2 for a duration of a minimum of 30 minutes in the wet condition
is considered to meet level 3 fire endurance standard.
2.2.1.3 System location matrix
2.2.1.3.1 The matrix in appendix 4 establishes fire endurance
requirements, which are system and location dependent, that pipe materials
installed in a specific system and location should possess to meet
accepted minimum levels of safety.
2.2.1.3.2 Where, according to the matrix, remotely
closed valves are required when permitting the use of plastic piping,
the remote operation system, should be designed such that its function
will not be inhibited after being exposed to an equivalent level 1
fire endurance test. Remote operation is defined as an accessible,
safe location outside the space in which the valves are installed.
In the case of valves on the main deck of a tanker, remote operation
should be from outside the cargo block.
2.21.3.3 Where the matrix stipulates level L2,
pipes of endurance Level L1 may also be used. Similarly, where the
matrix stipulates endurance Level L3, pipes of endurance level L2
and L1 may be used.
2.2.2 Flame Spread
2.2.2.1 All pipes, except those fitted on open decks and
within tanks, cofferdams, void spaces, piped tunnels and ducts if separated from
accommodation, permanent manned areas and escape ways by means of an A class
bulkhead, should have low flame spread characteristics as determined by the test
procedures given in appendix 3.
2.2.2.2 In appendix 3
the test sample configuration only considers flat surfaces. Procedure modifications
to the 2010 FTP Code, annex 1, part 5 are necessary due to the curvilinear pipe
surfaces. These procedure modifications are also listed in appendix 3.
2.2.2.3 Piping materials giving average values for all
of the surface flammability criteria not exceeding the values listed in appendix 3
are considered to meet the requirements for low flame spread in accommodation,
service and control spaces. In other areas or where the quantity of pipes is small,
the Administration may allow equivalent acceptance criteria.
2.2.3 Smoke Generation, Containment and Toxicity
2.2.3.1 Criteria for smoke production need only be
applied to pipes within the accommodation, service, and control spaces. SOLAS
regulation II-2/6 is applicable to exposed interior surfaces which are
interpreted as including the surface finish of piping systems.
2.2.3.2 Piping materials shall fulfil the requirements
of the 2010 FTP Code, annex 1, part 2, on smoke and toxicity test. Procedure
modifications are necessary due to the curvilinear pipe surfaces. These procedure
modifications are listed in appendix 3
2.2.4 Electrical Conductivity
2.2.4.1 Electrostatic charges can be generated on the
inside and outside of plastic pipes. The resulting sparks can create punctures
through pipe walls leading to leakage of pipe contents, or can ignite surrounding
explosive atmospheres. Administrations should consider these hazards when approving
plastic piping systems carrying fluids capable of generating electrostatics charges
(static accumulators) inside the pipe, and when approving plastic piping systems in
hazardous areas (i.e. areas that could, either in normal or fault conditions, contain
an explosive atmosphere), for the possibility of electrostatic charges outside the
pipe.
2.2.4.2 In practice, fluids with conductivity less than
1,000 pico siemens per metre (pS/m) are considered to be non-conductive and therefore
capable of generating electrostatic charges. Refined products and distillates fall
into this category and piping used to convey these liquids should therefore be
electrically conductive. Fluids with conductivity greater then 1,000 pS/m are
considered to be static non-accumulators and can therefore be conveyed through pipes
not having special conductive properties when location in non-hazardous areas.
2.2.4.3 Regardless of the fluid being conveyed, plastic
piping should be electrically conductive if the piping passes through a hazardous
area.
2.2.4.4 Where conductive piping is required, the
resistance per unit length of the pipe, bends, elbows, fabricated branch pieces,
etc., should not exceed 1 x 105 Ohm/m and the resistance to earth from any
point in the piping system should not exceed 1 x 106 Ohm. It is preferred
that pipes and fittings be homogeneously conductive. Pipes and fittings having
conductive layers may be accepted subject to the arrangements for minimizing the
possibility of spark damage to the pipe wall being satisfactory. Satisfactory
earthing should be provided.
2.2.4.5 After completion of the installation, the
resistance to earth should be verified. Earthing wires should be accessible for
inspection.
2.2.5 Fire Protection Coating
2.2.5.1 Where a fire protective coating of pipes and
fittings is necessary for achieving the fire endurance standards required, the
following requirements apply:
2.2.5.1.1 Pipes should be delivered from the
manufacturer with the protective coating on in which case on-site application of
protection would be limited to what is necessary for installation purposes (e.g.,
joints). Alternatively, pipes may be coated on site in accordance with the approved
procedure for each combination, using the approved materials of both pipes and
insulations.
2.2.5.1.2 The liquid absorption properties of the
coating and piping should be considered. The fire protection properties of the
coating should not be diminished when exposed to saltwater, oil or bilge slops. The
Administration should be satisfied that the coating is resistant to products likely
to come in contact with the piping.
2.2.5.1.3 Fire protection coatings should not degrade
due to environmental effects over time, such as ultraviolet rays, saltwater exposure,
temperature and humidity. Other areas to consider are thermal expansion, resistance
against vibrations, and elasticity. Ageing of the fire protection coatings should be
demonstrated to the satisfaction of the Administration in a manner consistent with
the ageing test specified above.
2.2.5.1.4 The adhesion qualities of the coating should
be such that the coating does not flake, chip, or powder, when subjected to an
adhesion test acceptable to the Administration.
2.2.5.1.5 The fire protection coating should have a
minimum resistance to impact to the satisfaction of the Administration.
2.2.5.1.6 Pipes should be an appropriate distance from
hot surfaces in order to be adequately insulated.
2.2.5.2 Special testing may be required as part of the
approval procedure.
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