2.2
DESIGN OF FOAM SYSTEMS
Design of [deluge] [pre-action] fire extinguishing foam systems shall be by
hydraulic calculations for uniform distribution of AFFF solution over the
protected area and shall conform to the NFPA standards listed above and to
the requirements as specified herein.
2.2.1
Sprinkler Heads
Heads shall have 15 [or 13.50] mm 1/2 [or 17/32] inch orifice. No o-rings
will be permitted in sprinkler heads. [For deluge systems, provide open
heads.] [For pre-action systems, the release element of each head shall be
of the ["intermediate"] ["high"] temperature rating or higher as suitable
for the individual location installed.] Provide chromium plated ceiling
plates and pendent sprinklers below suspended ceilings. Provide corrosion
resistant sprinkler heads and sprinkler head guards as required by NFPA 13.
2.2.2
Cabinet
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NOTE: Deluge systems do not require a sprinkler
head cabinet.
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Provide extra sprinkler heads and sprinkler head wrench in a metal cabinet
adjacent to the pre-action valve within each building. The number and types
of extra sprinkler heads shall be as specified in NFPA 13.
2.2.3
[Deluge] [Pre-Action] Valves
Valves shall be operated by a detection system listed for releasing service
and independent of the building fire alarm system. [[Deluge] [Pre-action]
valve clappers shall incorporate a latching mechanism that will not be
affected by changes of pressure in the water system.] If 150 mm 6 inch
valves are used in 200 mm 8 inch risers, provide smoothly tapered
connections. In addition to automatic operation, arrange each valve for
manual release at the valve. Provide pressure gages and other
appurtenances at the [deluge] [pre-action] valves as required by NFPA 13.
Provide a detection device at the end of each actuation circuit to test the
circuit and mount the device [adjacent to the valve] between 1.80 and 2.40
meters 6 and 8 feet above the finish floor. Label each testing device to
indicate the valve it activates. [Provide remote manual releases [at
[_____]] [where shown].]
2.2.4
AFFF Solution Distribution
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NOTE: Select the first option for pre-action
systems. Select the second option for deluge
systems.
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[Distribution shall be essentially uniform throughout the area in which it
is assumed the sprinkler heads will open. Variation in discharge from
individual heads in the hydraulically most remote area shall be between 100
and 115 percent of the specified density.]
[Distribution shall be essentially uniform throughout the area. Variation
in discharge from individual heads shall be between 100 and 115 percent of
SECTION 13956N
Page 16
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