Page: 43
MV & LV SERIES ENGINEERED DRY CHEMICAL FIRE EXTINGUISHING SYSTEM
OPERATION, DESIGN, & SERVICE MANUAL
REV C
Document # DOC324
Issued: April 26, 2018
Revised: March 22, 2022
UL FILE # EX27541
Figure 3.2.4.1 Nozzle Placement for Fixed
OriceTotalFloodApplication
3.2.4.1 Total Flood - Standard Coverage
3.2.4.1.1 Nozzle Orientation
e Total Flood (TF) Nozzle (P/N 16172) is
used for Standard Total Flood coverage. e
TF Nozzle has been developed to provide
application of extinguishing agent from an
overhead position. e nozzle is to be mounted
in the center of the protected area, with the tip of
the nozzle no greater than 6 in (152 mm) from
the ceiling. e nozzle coverages are shown in
Table 3.2.4.1.1a and 3.2.4.1.1b.
NOTE: e Janus Fire Systems® Engineered
Dry Chemical System has not been evaluated
by Underwriters Laboratories, Inc. with
respect to the total flood protection of hazards
incorporating unclosable openings exceeding
5% of the total hazard surface area.
Section 3 System Design
3.2.4 TotalFlood-FixedOrice
Fixed Orifice Total Flooding coverages are offered in two different versions: “Standard” and “Module
Perimeter”. e system designer must select the appropriate coverage to use prior to installation.
e Fixed Orifice Total Flood Discharge Nozzles have been tested by Underwriters Laboratories, Inc. with
respect to the total flood protection of hazards incorporating unclosable openings not exceeding 5% of
the total hazard surface area. If hazards have openings in excess of 5%, the openings can be protected with
inclusion of screening nozzles for unclosable openings up to 19% of the total hazard surface area.
As an alternative to the use of screening nozzles for the protection of total flooding applications where
the unclosable openings have areas between 5 percent of the total enclosure surface area enclosure and 15
percent, compensation shall be furnished by additional dry chemical in the proportion of not less than 1 lb/
ft² (4.88 kg/m²) of unclosed opening, applied simultaneously by local application over the openings.
NOTE: When using the screening nozzles to protect unclosable openings up to and not exceeding 19% of
the total enclosure surface area, additional supplemental dry chemical is not required.