When the Authority Having Jurisdiction requires direct impingement of water spray of the complete protected surface, the nozzles should be spaced
and directed so their spray pattern will completely cover the surface plane of the protected object or area. Use the minimum required average density
based on the included angle and the K-Factor based on the residual pressure at the inlet of the nozzles. Figure (see picture) indicate the coverage for
each nozzle’s included spray angle at various heights. Recommendation: Limit the maximum spacing of nozzles to 12 ft. (3.6 m) or less for indoor applications and 10 ft. (3 m) or less for outdoor applications.
For exposure protection of vessels using rundown and slippage, e.g., exposure protection of vessels per NFPA 15 section 7.4.2 (2007 edition), the preceding recommendations apply.
Figure (see picture) indicate the distance from the nozzles to the tangent surface of the protected object at various fixed angles. The fixed angle is the included angle from pendent position being zero of spray nozzle position.
The spray angle is the included angle of the spray nozzle pattern.
The maximum distance is determined where the spray pattern angle is unchanged at the perpendicular position to tangent of fixed angle.
The distances indicated are for 20 PSI (1.4 Bar) minimum, to 60 PSI (4.1 Bar) maximum residual pressure at the inlet of the nozzles.
When Spay Nozzles are used to protect surfaces of vessels, they should be positioned normal to the surface being protected and approximately 2 ft. (0,6 m) from the surface.
Using the proper spray angle and K-Factor with this approach will provide the most effective protection and minimize effects of wind or draft conditions on the water spray pattern of the nozzles
MAXIMUM AXIAL DISTANCE BETWEEN NOZZLE TIP AND PLANE-OF-PROTECTION FOR EXPOSURE PROTECTION — METERS SEE DATASHEET SPRAY NOZZLES!
IMPORTANT: Always refer to Datasheet spray nozzle supplier, the appropriate standards of
NFPA , FM Global, LPCB, APSAD, VdS or other similar organizations, and also with the provisions of governmental
codes, ordinances, and standards, whenever applicable.
#brand #brandbeveiliging #brandweer #deluge #exposure #fire #nozzle #protection #spray_nozzle #sprinkler #sprinklersystem