CEN Hazard Classification for Sprinklers and Water Mist

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CEN Hazard Classificationfor Sprinklers and
Water Mist
Dr. Maarit Tuomisaari Marioff Corporation Oy
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• EN 128452003 for sprinklers
• Hazard classification based on long-term
  experience
• Given hazard classification reflects the
  challenge to the
• 2-dimensional wetting of traditional water
  sprays.

• prCEN/TS 14972 for water mist systems
• No hazard classification specified.
• The sprinkler classification does not
  necessarily reflect the
• challenge to water mist systems that do not
  rely only on
• wetting but also on 3-dimensional inerting,
  cooling of gases
• and blocking of radiant heat.

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EN 128452003 for sprinklers Prescriptive
requirements OH1 OH2 OH3 OH4 Design density
(mm/min) 5 5 5 5 Area of
operation (m2) 72 144 216 360 Nominal
number of sprinklers 6 12 18 30
prCEN/TS 14972 for water mist systems Performance-
based requirements OH1 OH2 OH3 OH4 Design
density equivalent to 5 mm/min Area
of operation (m2) 72 144 216 360 Nominal
number of sprinklers depends on the coverage
area
(1
(1
(1 not a requirement but common practice
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EN 128452003 OH1 Occupancies
prCEN/TS 14972
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prCEN/TS 14972 OH1 Occupancies / offices
Reference sprinkler Pendent spray
sprinkler Special Response Nominal K factor
80 Temperature rating 68 ºC Fire tests Ignition
under one sprinkler Ignition between four
sprinklers Repetition of the worse one Criteria
to be defined Fire damage Temperatures
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prCEN/TS 14972 OH1 Occupancies / offices
Water Mist sprinkler To be defined in the
tests Fire tests Ignition under one
sprinkler Ignition between four
sprinklers Repetition of the worse
one Criteria Fire damage as per REF
Temperatures as per REF
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prCEN/TS 14972 OH1 Occupancies / offices
VdS approval coverage with an extensive number of
additional fire tests according to FM, IMO and
VdS test procedures

• Design criteria System A System B
• - water density lt 0.6 mm/min 1.5 mm/min
• coverage per sprinkler 12.25 m2 25 m2

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prCEN/TS 14972 OH1 Occupancies / offices

• Conclusions
• For OH1 type hazards the number of
• sprinklers activating is the same for both
• the sprinkler and referred water mist
• systems.
• Number of sprinklers is a more relevant
  
• design parameter than a fixed operation
• area.

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EN 128452003 OH3 Occupancies
prCEN/TS 14972 - proposal
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prCEN/TS 14972 - proposal OH3 Occupancies
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prCEN/TS 14972 OH3 Occupancies
VdS approval coverage with REF system operated at
8 mm/min instead of 5 mm/min

• Design criteria
• - water density 3.8 mm/min
• coverage per sprinkler 9 m2

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prCEN/TS 14972 proposal OH3 Occupancies

• Conclusions
• For OH3 type hazards the number
• of sprinklers activating is different
• for the sprinkler and referred water
• mist system.
• Number of sprinklers is a more
• relevant design parameter than a
• fixed operation area.

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prCEN/TS 14972 proposal OH3 Occupancies
Aspect that is not taken into account at all
REF17 700 LITRES WATER
WATER MIST4100 LITRES WATER
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Study on operation areas together with Dr.Jukka
Vaari, VTT, Finland
2 MW concealed pallet pile2 MW open pool4 m
2.5 m ceiling heights
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2 MW concealed pallet pile / 2.5 m ceiling height
REF
WATER MIST
Number of sprinklers activating in the
tests REF (5 mm/min) Water Mist System
(OH1) 4 15 / 184 m2 1
4 / 100 m2
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61.25 m2 - 3 mm/min
80 m2 - 2.3 mm/min
100 m2 - 1.5 mm/min
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• SUMMARY
• Prescriptive requirements of EN 12845 may well
  be justified
• based on the long-term experience with
  sprinklers.
• Prescriptive dimensioning of EN 12845 based on
  fixed
• prescripitive hazard classification should not
  be mixed with
• the performance based design of prCEN/TS 14972
• Number of nozzles is a more relevant design
  parameter
• than a fixed area
• Relevant design fires instead of fixed hazard
• classification to be developed for defining
  the design
• number of nozzles
• Experience and dedicated research will lead to
• performance-based hazard classification,
  i.e.
• correspondence between each design fire and
  different
• hazard types.

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THANK YOU !