Fire Fighting System Design for Buildings in Pune: Tanks, Pumps and the Fire NOC

What the fire fighting design covers

The fire fighting system is the part of a building's services the fire authority checks before it grants the fire NOC, and the part that decides some of the largest spaces in the building: a fire tank in the basement or under the yard, a pump room beside it, a tank on every terrace and a fire shaft through every floor. Those spaces have to be on the architect's plans and in the structure before the first slab is cast, so the fire design starts with the first set of drawings, not at the end.

On a typical Pune project, the fire fighting design includes:

• Fire water storage: the underground or ground-level fire tank and the terrace fire tanks
• The pump room: hydrant, sprinkler and jockey pumps, with standby or diesel-engine pumps where needed, and their headers and valves
• Hydrants: wet risers with landing valves and hose reels at the fire stairs, and a hydrant ring round the building
• Sprinklers: in the basements and parking, and inside flats, offices and kitchens where the building needs them
• Fire-brigade inlets and the draw-out connection that lets fire engines pump from the fire tank
• Fire alarm: detectors, manual call points, hooters and the fire alarm panel
• Extinguishers, placed to IS 15683
• The services that work with the fire system: basement ventilation in fire mode, staircase and lift-well pressurisation, and the power supply for the fire pumps

Fire water storage grows with the building

The fire water a building must store depends on its height, its use and its floor area, and the fire authority sets the volumes it will accept. A low residential building may need only a fire tank on the terrace; a high-rise needs a large underground tank as well, with a tank on every tower roof. The sizes from our residential projects in Pune show how quickly the storage grows:

Where the fire tank goes

An underground fire tank is usually built beside the pump room, under a basement or a ramp, and it is one of the deepest and heaviest parts of the structure. On the Ravet tower, the fire tank sits with the domestic, drinking and raw water tanks beside a 78 sq m pump room, and every pipe through the tank walls - inlets, overflows, the test drain and the pump suctions - was given a sleeve size and a level on a 17-sleeve chart before the walls were cast.

The pumps

A fire pump room normally has a hydrant pump, a sprinkler pump and a small jockey pump that keeps the pipes under pressure, so the main pumps start only when water is drawn. The head of the pumps grows with the height of the building, and the power they need sets part of the diesel generator size, because the fire pumps must run when the mains supply fails. On the Taloja school, for example, a 160 kVA DG set is provided for the common and fire loads - see how the load and DG set are calculated.

Hydrants and sprinklers inside the building

Inside a residential tower, the fire design is mostly vertical: a riser in the fire shaft with a landing valve and hose reel at every floor, and on taller towers, sprinklers inside the flats. On the Mantra towers at Balewadi, each floor has a flow switch and a test-and-drain valve on the riser, so a sprinkler that opens shows on the panel by floor and each floor can be tested without draining the tower.

Basement parking is usually the largest sprinklered area. Stack parking needs more than one layer of sprinklers - on the Ravet tower, the stack parking has an upper and a lower sprinkler zone. The heads are chosen room by room: on the Taloja school, pendent, upright and sidewall heads at 68 °C, with 79 °C sidewall heads in the kitchen.

Outside, a 150 mm hydrant ring with single-headed hydrants and hose boxes runs round the building, and the fire-brigade inlets and the draw-out connection are placed where the fire engines can reach them from the fire drive way.

Industrial sheds

A large shed is a fire problem before it is anything else: a wide, open volume under a high roof, where a fire can spread across a large area quickly. On the Chakan shed, about 157 x 56 m under one roof, the design has quick-response K-80 sprinklers throughout, a 150 mm hydrant main along the 6 m fire drive way, and a water curtain along the walls on its own pump, so it does not take water from the sprinklers. On the Navlakh Umbre shed, a 150 kL tank beside the pump room feeds a 150 mm hydrant ring round the shed, with a tapping for the shed's internal system.

Fire water that ends up in the basement

When sprinklers open in a basement, the water has to go somewhere. We size the basement dewatering sumps for it: on the Bhukum township, 17 kL for every 3,000 sq m fire zone, from 30 sprinklers discharging for ten minutes. On the same project, the basement ventilation doubles its air changes in fire mode, and the staircases and lift wells are pressurised to 50 Pa so smoke stays out of the escape routes.

Designing for the fire NOC

The fire NOC is often handled with a licensed fire agency, and the volumes and pumps the fire authority accepts can differ from a first calculation. On the Katraj project, the water calculation was reissued to meet the fire NOC, with the basement fire tank increased to 50 kL. On the Daund food-processing sheds, the fire volumes are to be confirmed with the fire-licensing agency and the fire NOC before the tanks are built.

The safe order is to agree the fire water and pumps with the fire agency while the basement and the pump room can still change, and to issue the tank, pump room and shaft sizes to the architect and the structural engineer together with the water and electrical calculations, so the domestic and fire tanks, the DG set and the pump room all fit in one layout.

What to send

To design the fire fighting system for your building, we need:

• The architectural plans, sections and the building height
• The use of every floor, and the number of flats, shops or offices
• The number of basements and the parking type (open, stack or puzzle)
• The site plan with the fire drive way and the road widths
• The fire agency's or the fire authority's comments, if you already have them

Our fire fighting work

We design fire fighting systems as part of the full MEPF design for residential towers, offices, schools, hospitals and factories across Pune and Pimpri-Chinchwad, from the tank and pump sizes to the layouts for every floor - see MEP consultants in Pune, or send your drawings for a free project review.