Page 121 - Water Engineering Hydraulics, Distribution and Treatment

Required fire flow for buildings
Table 4.13
2
2
a
Type of building construction
b
c
Type I-A
Type V-B
noncombustible,
Duration
Fire flow
combustible,
gpm (L/min)
unprotected
protected
1,500 (5,678)
0–22,700 (0–2,109)
0–3,600 (0–334)
1,750 (6,624)
22,701–30,200 (2,110–2,806)
2,000 (7,520)
4,801–6,200 (447–576)
30,201–38,700 (2,807–3,595)
38,701–48,300 (3,596–4,487)
2,250 (8,516)
6,201–7,700 (577–715)
2
7,701–9,400 (716–873)
48,301–59,000 (4,488–5,481) Area ft (m ) 3,601–4,800 (335–446) 4.4 Variations or Patterns of Water Demand (h) 99
2,500 (9,463)
59,001–70,900 (5,482–6,587) 9,401–11,300 (874–1,050) 2,750 (10,409)
70,901–83,700 (6,588–7,776) 11,301–13,400 (1,051–1,245) 3,000 (11,355)
83,701–97,700 (7,777–9,076) 13,401–15,600 (1,246–1,449) 3,250 (12,301) 3
97,701–112,700 (9,077–10,470) 15,601–18,000 (1,450–1,672) 3,500 (13,248)
112,701–128,700 (10,471–11,956) 18,001–20,600 (1,673–1,913) 3,750 (14,144)
128,701–145,900 (11,957–13,554) 20,601–23,300 (1,914–2,165) 4,000 (15,140)
145,901–164,200 (13,555–15,254) 23,301–26,300 (2,166–2,443) 4,250 (16,086)
164,201–183,400 (15,255–17,038) 26,301–29,300 (2,444–2,722) 4,500 (17,033)
183,401–203,700 (17039–18,927) 29,301–32,600 (2,723–3,029) 4,750 (17,979)
203,701–225,200 (18,928–20,921) 32,601–36,000 (3,030–3,344) 5,000 (18,925)
225,201–247,700 (20,922–23,011) 36,001–39,600 (3,345–3,679) 5,250 (19,871)
247,701–271,200 (23,012–25,194) 39,601–43,400 (3,680–4,032) 5,500 (20,818)
271,201–295,900 (25,195–27,489) 43,401–47,400 (4,033–4,403) 5,750 (21,764)
295,901–greater (27,490–greater) 47,401–51,500 (4,404–4,784) 6,000 (22,710) 4
— (—) 51,501–55,700 (4,785–5,175) 6,250 (23,656)
— (—) 55,701–60,200 (5,176–5,593) 6,500 (24,603)
— (—) 60,201–64,800 (5,594–6,020) 6,750 (25,549)
— (—) 64,801–69,600 (6,021–6,466) 7,000 (26,495)
— (—) 69,601–74,600 (6,467–6,930) 7,250 (27,441)
— (—) 74,601–79,800 (6,931–7,413) 7,500 (28,388)
— (—) 79,801–85,100 (7,414–7,906) 7,750 (29,334)
— (—) 85,101–greater (7,907–greater) 8,000 (30,280)
Source: Data from International Fire Code (ICC, 2006).
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Conversion factors: 1 ft = 0.0929 m , 1 gpm = 3.785 L∕min.
a The specified area shall be the area of the three largest successive floors.
b Typically these are concrete-frame buildings made of noncombustible materials. “A” stands for protected.
c Typically these are wood-frame buildings. “B” stands for unprotected.
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by up to 75% for larger buildings (exceeding 3600 ft or ment of a serious fire. Coincident draft of water for pur-
2
344 m ) when buildings are fitted with automatic sprinkler poses other than firefighting is rarely assumed to equal the
systems. maximum hourly rate. Depending on local conditions, the
Standard fire requirements take into account proba- maximum daily rate may be a reasonably safe assumption
ble loss of water from connections broken in the excite- instead.
EXAMPLE 4.2 DETERMINATION OF CAPACITIES OF WATERWORKS SYSTEMS
The four typical waterworks systems shown in Fig. 4.4 supply a community with an estimated future population of 120,000.
Determine the required capacities of the constituent structures for an average consumption of 150 gpcd (568 Lpcd) and a distributing
reservoir so sized that it can balance out differences between hourly and daily flows, fire demands, and emergency requirements.
Assume a requirement for fire protection that is needed to control two simultaneous fires in two unprotected wood-frame construction,
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2
multistory buildings having a 12,000 ft (1,115 m ) area per floor.