46.03
16398 Rev B Updated 04/2021 © 2021 Victaulic Company. All rights reserved.
5.0 PERFORMANCE (CONTINUED)
Hydraulic Criteria For Hip With Hip Truss/Jack Truss Construction – Wet System Only
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 – 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 20A and Figure 20B.
• Minimum sprinkler flow rate is 20 gpm per sprinkler.
Calculation #2 – Upper Hip Area
If there are 4 sprinklers or less in the shaded area (Figure 20A):
• 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 rate is 20 gpm per sprinkler.
If there are more than 4 sprinklers in the shaded area (Figure 20B):
• 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 rate is 20 gpm per sprinkler.
• Example shown in FIGURE 20B results in 12 sprinklers to be calculated. (18 x 0.75 = 12)
FIGURE 20A
FIGURE 20B
FIGURE 20: HYDRAULIC CALCULATIONS REQUIRED FOR HIP – WET SYSTEM (HIP TRUSS/JACK TRUSS CONSTRUCTION)
FL-SA/GAP
FL-SA/DS
19
