In multi-story buildings a type of rigid water piping is provided to connect fire hoses. Within buildings these pipes serve the same purpose of fire hydrants. This system allows manual application of water to the fire. Dear readers, these pipe is called Standpipe. In this post I shall discuss Design consideration for Standpipe and Hose System
1.The fire protection system shall be designed for their effective use either by amateur or trained fire fighting personnel or both.
Building
Type
|
Sprinkler
System (l/min)*
|
Standpipe
and Hose system (l/min)*
|
Duration**
(min)
|
Light hazard - I
|
1000
|
1000
|
30
|
Light hazard - II
|
1900
|
1900
|
50
|
Ordinary hazard - I
|
2650
|
1900
|
75
|
Ordinary hazard - II
|
3200
|
1900
|
75
|
Ordinary hazard - III
|
4800
|
1900
|
75
|
Notes:
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* Values will
be for one riser serving floor area of 1000 m2.
**These duration shall be for a
building up to the height of 51 m. For greater height of 51-102 m and above 102 m, the duration will be 1.25
times and 1.5 tomes of the specified values respectively.
|
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Light hazard – I : Occupancy groups, A1, A2, A4
Light hazard – II : Occupancy groups, A3, A6, A8, B, C,
D, E4, E7, F1 & F2
Ordinary hazard – I : Occupancy groups, E1, E3, E5, F3, F4, F5,
F6, F7, G1 & G4
Ordinary hazard – II : Occupancy groups, G2 & H1
Ordinary hazard – III : Occupancy
groups, G3 & H2
Extra hazard : Occupancy groups, j
– pressure and flow requirement for this group shall be determined by Fire
Department but shall not be less than required value for Ordinary hazard-III
|
2. All standpipes in standpipe system shall be sized so that they will provide a minimum flow specified in Table-1. In standpipe system with more than one standpipe, the supply piping shall be sized for the minimum flow specified in Table-1 for the first standpipe plus 1000 litre per minute for such additional standpipe. The total number of such additional standpipes shall not be more than 8. All standpipe risers shall be connected through a gate valve with a main of size equal to that of the largest riser.
3. The minimum pressure for standpipes supplying a 50 mm or larger hose shall be at least 300 Kpa. For standpipe supplying first aid hose (38 mm nominal) may have a minimum pressure of 200 Kpa.
4. The size (diameter) of stand pipes for various building height may be as shown in Table -2 or hydraulically designed to provide the required flow and pressure, stated above, at the topmost outlet.
Table-2 : Standpipe Sizes
No.
of Storeys
|
Building
Height(m)
|
Size
of Stand pipe(mm)
|
Up to
5
|
UP to 17
|
75*
|
Up to
10
|
UP to 33
|
100
|
10 to
20
|
33 to 63
|
150
|
20to
54
|
63 to 65
|
200
|
*These pipe may be used only for occupancy groups A1, A2
and A4
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5. The water supply required for combined system (for partial automatic sprinkler and Fire Department hose) shall be calculated in accordance with (2) above plus an amount equal to the hydraulically calculated sprinkler demand or 550 litre per minute for light hazard occupancy groups or 1900 litre per minute for ordinary hazard occupancy groups.
Table-3 : Piping for Standpipe System
Materials
|
Standard
|
Copper Tube
|
ASTM
B75, ASTM B88
|
Copper and
Copper-Alloy Tube
|
ASTM
B251
|
Steel Pipe
|
ASTM
A55, ASTM A120, ASTM A135
|
Wrought Steel or
Iron
|
ANSI
B36.10
|
6. The size of combined system shall be at least 150 mm or hydraulically designed to provided the required flow (5) and pressure.
7. The standpipe shall be located in noncombustible enclosure such that it will be able to provide hose stream to the most remote area of the floor served.
Table-4 : Standpipe
Fittings
Materials
|
Standard
|
Cast Iron
|
ANSI
616.1, ANSI B 16.4
|
Copper
|
ANSI
B16.18, ANSI B16.22
|
Malleable Iron
|
ANSI
B16.3
|
Steel
|
ANSI
B16.5, ANSI B16.9, ANSI B16.11, ANSI B16.25, ASTM A234
|
8. The hose shall be connected to the standpipe within 1.5 m from the floor. Hose stations shall be easily accessible for inspection and testing.
Standpipes are most commonly built in buildings in vertical position. These make fire fighting for the fire fighters easier. Just by connecting the fire hoses to it.
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