SECTION 9 – APPENDIX
UL EX3470 ULC EX3470
2014-SEP-01 REV. 11 PAGE 9-15
R-102 Restaurant Fire Suppression Manual
MULTIPLE NOZZLE FRYER PROTECTION CALCULATION
EXAMPLES
Example No. 1 – Donut Fryer Without Dripboard. This fryer
has a frypot that measures 26 in. depth x 28 in. length (660 mm
x 711 mm). Because the frypot exceeds the maximum dimen-
sions for one nozzle, multiple nozzles will be required.
Procedure:
Find the area of the fryer by multiplying the 26 in. depth
x the 28 in. length (660 mm x 711 mm) which equals
728 in.
2
(46,967 mm
2
). Using the 3N nozzle (approved for
fryers with the longest side of 25 3/8 in. (644 mm) and a
maximum of 370.5 in.
2
(23,903 mm
2
) in area), divide the total
area of 728 in.
2
(46,967 mm
2
) by 370.5 in.
2
(23,903 mm
2
) to
find the number of nozzles needed. 728 in.
2
(46,967 mm
2
)
divided by 370.5 in.
2
(23,903 mm
2
) per nozzle = 2 nozzles
required. Then, verify the maximum longest side dimension
of 25 3/8 in. (644 mm). Doing this will require doubling the
3N nozzles to = a total of 4 nozzles, if we are to protect the
26 in. (660 mm) depth and the 28 in. (711 mm) length of the
fryer with this 3N nozzle option. See Figure 9-1.
Using the same process, but utilizing the 3N nozzle approved
for fryer protection with the longest side of 27 5/8 in. (702
mm) and the maximum of 324 in.
2
(20,903 mm
2
) in area,
the calculation will change to 728 in.
2
(46,967 mm
2
) divided
by 324 in.
2
(20,903 mm
2
) per nozzle = 3 nozzles. Because
this 3N nozzle option will protect 27 5/8 in. (701 mm) on
the longest side, it will protect the 26 in. (660 mm) side in
this example, thus eliminating the need for extra nozzles.
Utilizing this option, in this example, will require a total of 9
flows, but allows less nozzles and less nozzle drops*. See
Figure 9-1.
* Note: 2-flow appliance nozzles can also be used. This option
requires a total of 4 nozzles (728 in.
2
(46,967 mm
2
) divided by
210 in.
2
(13,548 mm
2
) per nozzle = 4 nozzles, or 8 total flows).
Using this option requires that the nozzles be placed over each
quadrant of frypot area protected and aimed to the center of the
modules. This option may be desirable if minimizing total system
flows is important.
FIRST 3N NOZZLE OPTION
SECOND 3N NOZZLE OPTION
28 IN.
(711 mm)
26 IN.
(660 mm)
13 IN.
(330 mm)
26 IN.
(660 mm)
14 IN.
(355 mm)
9 3/8 IN.
(238 mm)
9 3/8 IN.
(238 mm)
9 1/4 IN.
(234 mm)
28 IN.
(711 mm)
FIGURE 9-1
002466
Example No. 2 – Fryer With Dripboard. This fryer has an
overall fry vat, including a dripboard, that measures 24 in.
(609 mm) in depth x 20 in. (508 mm) in length. The actual frypot
measures 20 in. x 20 in. (508 mm x 508 mm). Because both the
frypot and the overall fry vat including the dripboard exceed the
maximum dimensions for one nozzle, multiple nozzles will be
required.
Procedure:
Divide the fryer cooking area from left to right or from front
to back into modules that do not exceed single nozzle area
limitations and longest side limitations as described in the
table for “Fryer Multiple Nozzle Protection” located in the
Design Section.
The example fryer can either be divided from left to right
into two modules, each measuring 10 in. x 24 in. (254 mm x
609 mm), or it can be divided from front to back. See Figure
9-2.
If the fryer is divided from front to back, two 2-flow nozzles
may be adequate. To determine this, first protect as much
of the rear portion of the vat (the frypot area) that is allowed
with 2-flow appliance nozzles using the maximum area of
210 in.
2
(13,548 mm
2
) per nozzle with the maximum longest
side of 21 in. (533 mm) for multiple nozzles. See Figure 9-2.
In the example, the frypot is 20 in. (508 mm) from side
to side. Use the maximum area of 210 in.
2
(13,548 mm
2
)
allowed for one nozzle and divide it by 20 in. (508 mm), a
total of 10 1/2 in. (266 mm) of the frypot can be protected
with one 2-flow nozzle (210 in.
2
divided by 20 in. = 10.5 in.).
See Figure 9-2.
This leaves the remainder of 9 1/2 in. (241 mm) of frypot
and the entire dripboard yet to protect. One 2-flow appli-
ance nozzle will protect up to 10 1/2 in. (266 mm) of frypot,
therefore, there is no need to verify the remaining 9 1/2 in.
(241 mm). There is only the overall of 9 1/2 in. (241 mm)
remaining plus the dripboard to verify.
The dripboard measures 4 in. x 20 in. (101 mm x 508 mm),
with an overall remainder of dripboard area size
of 13 1/2 in. x 20 in. (342 mm x 508 mm) = 270 in.
2
(17,419 mm
2
). Reviewing the “Multiple Nozzle Fryer Table,”
a 2-flow appliance nozzle can protect an area, including
dripboard, of 294 in.
2
(18,967 mm
2
) with a longest side of
21 in. (533 mm). Because the area is less than the maximum
of 294 in.
2
(18,967 mm
2
) and the longest side is less than
the maximum of 21 in. (533 mm), a 2-flow nozzle will be
sufficient. See Figure 9-2.
Summary of Contents for R-102
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