46.02
16397 Rev A Updated 03/2021 © 2021 Victaulic Company. All rights reserved.
5.0 PERFORMANCE (CONTINUED)
Hydraulic Design
Hip Roof Calculation Procedure
When a Hip is included in the design of the attic, there
are three calculations required. One calculation for the
“Ridge/Hip Transition” area. The second and third
calculations determine the pipe sizing for the Hip area
itself. For the purposes of these hydraulic calculations
the Hip is broken into two areas; the “Lower Hip” area;
and the “Upper Hip” area. See above figure.
Hip Calculation (Hip Truss/Jack Truss Construction) -
Wet System
Calculation #1 – Ridge/Hip Transitions
• Calculate the most demanding 7 contiguous
sprinklers with a maximum of 5 sprinklers along the
ridge plus the 2 most demanding sprinklers within
the hip area. See Figure 18A.
• Minimum sprinkler flow is 20 gpm per sprinkler.
Calculation #2 – Lower Hip Area
• Calculate up to the 7 most demanding contiguous
sprinklers along the eave. This may include
sprinklers on both sides of the hip line as shown.
See Figure 18B.
• Minimum sprinkler flow is 20 gpm per sprinkler.
Calculation #3 – Upper Hip Area
If there are 4 sprinklers or less in the shaded area
(Figure 18B):
• Calculate up to the 7 most demanding contiguous
sprinklers in the "Upper Hip" area. This may include
sprinklers on both sides of the hip line as shown.
• Minimum sprinkler flow is 20 gpm per sprinkler.
If there are more than 4 sprinklers in the shaded area
(Figure 18C):
• Calculate the hydraulically most demanding 75%
of the total number of sprinklers located within
the "Upper Hip" area, rounding up to the nearest
sprinkler. (Minimum number of sprinklers to be
calculated is 7)
• Minimum sprinkler flow is 20 gpm per sprinkler.
– Example shown in Figure 18C results in 9 sprinklers to
be calculated. (12 x 0.75 = 9)
FIGURE 18A
FIGURE 18B
FIGURE 18C
FIGURE 18: HYDRAULIC CALCULATIONS REQUIRED FOR HIP - WET SYSTEM
(HIP TRUSS/JACK TRUSS CONSTRUCTION)
•
= RE
■
= DS
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