Fire Protection Plumbing

Water required for interior fire protection

The minimum quantity of water for sprinkler and hose use within the building according to their occupancy classification shall be in accordance with table -1 indicating fire protection flow requirements or on the basis of the hydraulic design of the system.

Water source for fire protection 

Water required for interior fire protection of a building shall be supplied from one or a combination of the following sources:

Table-1 : Fire Protection Flow Requirements

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: * 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. 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

Direct connection to water main

For continuous water supply (public water supply system or independent system only for fire protection) with sufficient quantity and pressure to feed fire fighting equipments during peak demand period, direct connection of the fire fighting system to the water main may be adopted (Fig-1).

Roof gravity tanks

For water supply system with inadequate quantity or pressure during peak demand period but with sufficient pressure to feed roof tank, a roof gravity tank shall be provided to feed fire fighting equipments(Fig-2).

Storage tank

For water supply system with inadequate pressure to feed fire fighting equipments or roof gravity tank, the building premises shall have a ground ( or under ground) tank to store water for fire fighting and one of the combination shown in Fig 3,4,5 shall be adopted.

The system only for fire fighting purpose may be designed with automatic fire pump as shown in Fig 3. The water supply system for domestic use and fire protection may be designed with roof gravity tank and manually controlled pump as shown in Fig 4. The pressure tank with automatic fire pump and the compressor may be used for supplying water to the fire fighting equipment as shown in Fig 5 and Fig 6. The location of the pressure tank shall be such that it will provide the required pressure at the highest fire fighting equipment.

The water stored in storage tank for fire fighting operation shall be used for other purposes ( see Fig-7).

The ground storage tank shall be easily accessible to fire engine of fire Department. In absence of space available for fire engine, the cover slab of ground storage tank shall be designed to withstand a vehicular load of local fire engine.

Individual Water sources

In absence of public water supply system, the building premises shall have individual water sources as specified in the post linked here. The individual water sources with adequate yield during peak demand period will serve as a fire service ground tank as shown in Fig-3, Fig-4, Fig-5. Otherwise, the water of the individual sources shall have to be stored in a tank as specified in storage tank section.

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.

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

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.

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.

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.

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

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