FOAM EXTINGUISHING SYSTEMS
6.1 FOAM EXTINGUISHING PUMPS: Foam extinguishing pumps shall be
designed in accordance with NFPA 20 (1993 edition).
6.2 SOLENOID OPERATED VALVES: All solenoid operated valves shall be
equipped with manual release or manual bypass.
6.3 ORIFICE PLATES: Orifice plates installed in pipelines for
purposes of reducing pressure are prohibited. Orifice plates used for
proportioning foam concentrate and water are allowed.
6.4 FOAM WATER DELUGE (CLOSED-HEAD) SYSTEMS: On Navy and Air Force
projects, primary aircraft hangar protection shall be closed-head foam
water deluge systems at roof level and floor level foam water monitor
nozzles. These closed-head foam water systems shall not exceed 15,000 sq.
ft. per riser.
6.5 CLOSED-HEAD FOAM WATER SPRINKLER SYSTEMS: Closed-head foam water
sprinkler systems shall be pre-action type for flammable liquid warehouses,
hazardous waste storage, etc.
6.6 POL ABOVEGROUND STORAGE TANKS: Foam extinguishing systems for
POL above ground storage tanks can be either "over-the-top" application
using foam chambers or subsurface injection per NFPA 11 (1988 edition).
New aboveground POL tanks shall be equipped with internal floating pans of
honeycombed aluminum or steel and these POL tanks shall be protected in
accordance with paragraph 4.14.2 of MIL-HDBK-1008B.
6.7 FOAM PIPING MATERIALS:
Foam piping materials to be compatible
with agent for long term use.
6.8 ELECTRIC EQUIPMENT IN HANGARS: Electric equipment beneath
sprinkler systems in hangars shall be weatherproof except for overhead
crane rails which can not be made weatherproof.
6.9 NEW FOAM WATER SYSTEMS:
All new foam water systems shall use 3%
6.10 BLADDER TANKS: Bladder tanks can be used in foam systems on a
case-by-case basis subject to approval of PACNAVFACENGCOM Code 408. Use
foam pumps and atmospheric tanks for most projects.