Quick Reference-Fire Fighting (Part-5)
December 11, 2023 Leave a comment
|
Fire Pipe Support |
||
| Hanger rod diameter (mm) | Nominal Pipes Diameter (mm) | Spacing between supports (meter) |
| Up to 25MM | 8MM | 2MM |
| 32 to 50MM | 8MM | 2.5MM |
| 65 to 80MM | 10MM | 2.5MM |
| 100MM | 12MM | 2.5MM |
| 150MM | 16MM | 3MM |
| 200MM & above | 16MM | 3MM |
| Extra supports shall be provided at the bends and at heavy fittings like valves to avoid undue stress on the pipes. | ||
|
Support Spacing for Steel Pipe (ASME B31.1) |
||
| Pipe Size | Water | Gas |
| 25.4 MM | 2133.6 MM | 2743.2 MM |
| 50.8 MM | 3048 MM | 3962.4 MM |
| 76.2 MM | 3657.6 MM | 4572 MM |
| 101.6 MM | 4267.2 MM | 5181.6 MM |
| 152.4 MM | 5181.6 MM | 6400.8 MM |
| 203.2 MM | 5791.2 MM | 7315.2 MM |
| 304.8 MM | 7010.4 MM | 9144 MM |
| 406.4 MM | 8229.6 MM | 10668 MM |
| 508 MM | 9144 MM | 11887.2 MM |
| 609.6 MM | 9753.6 MM | 12801.6 MM |
|
Thumb Rules for Pipe Support Spacing |
| As a rule of thumb, the spacing of pipe supports for steel pipes in liquid service, expressed in feet, may be taken as the nominal pipe size, expressed in inches, plus ten. For example, the spacing of pipe supports on a 6″ line will be approximately 6 + 10 = 16 feet |
|
The Minimum Rate of Flow (NBC-2016) (Table 6.10.2.1.3) |
||
| Nominal Pipe Size | Flow Rate | Flow Rate |
| 50 MM | 100 gpm | 380 L/Min |
| 65 MM | 150 gpm | 568 L/Min |
| 75 MM | 220 gpm | 833 L/Min |
| 100 MM | 390 gpm | 1500 L/Min |
| 125 MM | 610 gpm | 2300 L/Min |
| 150 MM | 880 gpm | 3350 L/Min |
| 200 MM | 1560 gpm | 5900 L/Min |
| 250 MM | 2440 gpm | 9250 L/Min |
| 300 MM | 3520 gpm | 13300 L/Min |
|
Size of Mains (NBC-2016) Table 8 |
||
| Size of the Mains | Type of Building | Remarks |
| 100 mm with single outlet landing valves |
(a) Residential building (A): | – |
| 1) Dormitories | – | |
| 2) Apartments | – | |
| 3) Hotels | Up to 45 m height | |
| (b) Educational buildings (B) | – | |
| (c) Institutional buildings (C) | Up to 30 m height | |
| (d) Assembly buildings (D) | – | |
| (e) Business buildings (E) | Up to 45 m height | |
| (f) Mercantile buildings (F) | – | |
| (g) Industrial buildings (G) | Up to 15 m heigh | |
| 150 mm with single outlet landing valves |
a) Hotels | Above 45 m height |
| b) Starred hotels | ||
| c) Institutional buildings (C) | Above 30 m height | |
| d) Business buildings (E) | Above 45 m height | |
| e) Industrial buildings (G) | Above 15 m height | |
| f) Storage buildings (H) | Up to 15 m height | |
| g) Hazardous buildings (J) | Up to 15 m height | |
|
Concealed Spaces Fire Protection (CPWD) |
|
| 9.4.9.1 | If the height of the concealed space at roof and floor is not greater than 0.8meter, the spaces shall be sprinkler protected only if they contain combustible materials or are constructed with combustible materials. Electrical cables with voltage less than 250 V, single phase, with a maximum of 15 cables per tray, are allowed. |
| 9.4.9.2 | Spaces between roofs and ceiling more than 0.8 m deep shall be sprinkler protected as follows: |
| (i) Concealed spaces less than 5m2 in area shall not require sprinkler protection. | |
| (ii) Sprinkler heads shall be provided considering the space as any other area in the building. | |
| (iii) Sprinkler heads may be connected individually with the range/distribution pipes below, which shall be sized by taking the room and concealed space sprinklers cumulatively. | |
| (iv) Sprinkler heads for concealed space and for the room may be connected with separate range / distribution pipes connected, with common feed pipe. The common feed pipes shall be not less than 65 mm diameter. | |
|
Fire Fighting Accessories (CPWD) |
|
| Yard Hydrant (External Hydrant) | Yard hydrants a ring of pipe shall be laid underground around the building at a minimum distance of 2 Meter but not more than 15 Meter from the building face. All internal risers shall be connected with this ring. |
| The yard hydrants shall be easily accessible and should normally be provided near boundary wall/along road | |
| At least one External Hydrant post shall be provided for every 45 Meter | |
| All Yard hydrant outlets shall be situated 1 Meter above ground level. | |
| The stand posts shall be 80 mm in diameter for single headed hydrants. | |
| Underground pipe shall be laid at least 2m away from the face of the building preferably along the roads and foot paths. As far as possible laying of pipes under road, pavement and large open spaces shall be avoided. Pipes shall not be laid under buildings and where unavoidable, these shall be laid in masonry trenches with removable covers and cut-off valves shall be provided at points of entry and exit. | |
| Fire Service Inlet | In order to facilitate feeding of water in the system by fire service, a 2 or 3 Way 63 mm diameter collecting head shall be provided and connected with each riser/down comer and the ring main with non-return valve and butterfly/sluice valve. This should be located at a place where fire brigade tender can reach. |
| Fire Service connection | It is for feeding water to underground storage tank by fire tenders. The static water storage tank shall be provided with a fire brigade collecting head with 4 number 63 mm diameter instantaneous male inlets arranged in a valve box at a suitable point at street level. |
| Fire Brigade draw out collecting head | Each of the static water storage tanks shall also be provided with a fire brigade draw out collecting head with 63 mm diameter instantaneous male draw out arranged in a valve box at a suitable point at street level. This draw out shall be connected to galvanized iron pipe of 100 mm diameter with foot valve arrangement in the tank. |
| Pump House | The pump house at ground level shall be easily accessible for firefighting operations and at least 6 meters away from all surrounding buildings and overhead structures. |
| Size of the pump house shall be not less than 6.0 m (W) x 8 m (L) x 3.5 m (H). If two electrical pumps are to be provided, the length of the pump house shall be not less than 12 meter. If the water supply pumps are to be installed in the same pump house, then either the width of pump house be increased by 1 meter or length be increased by 2 meter or suitably as is necessary. | |
| Ventilators at least 500 mm height shall be provided on three sides for natural light. | |
| The pump and motor/engine assembly shall be installed on suitable RCC foundation. The length and width of the foundation shall be such that 100 mm space is left all around the base frame. | |
| The height of foundation shall be so decided that the total weight of foundation block is 1.5 times the operating weight of the pump assembly. | |
| The foundation shall be isolated from the floor by vibration isolating pads. Angle iron frame of size 35 mm x 35 mm x 3 mm shall be provided on the top edges of the foundation | |
| More than one pump and motor assembly shall not be installed on a single base or cement concrete block. | |
| A minimum clearance of 1 meter around the main pumps shall be provided. For jockey pump-clearance of 75 cm shall be adequate. | |
| Internal Hydrant | A masonry enclosure on three sides of size minimum 1200 mm wide and 800 mm deep and 2100 mm height shall be provided |
| Cut-out of size 200 mm x 200 mm be provided in one corner in the slab for down comer/wet riser pipe. If sprinkler installations are to be provided, additional cut out of similar size for sprinkler pipe and drain pipe as the case may be, shall be provided. | |
| Internal hydrant shall be easily accessible. A clear space of at least 1.5 meter should be available in front of the internal hydrant for operation. Internal hydrant shall not be provided in a lockable room. | |
| Internal hydrant shall be clearly marked with the inscription of “FIRE HOSE CABINET” of letter size 75 mm in height and 12 mm in width by luminous sign. Sui | |
| FIRE CONTROL ROOM | For all buildings 15 meter in height or above, and apartment buildings with height 30 m and above, a fire control room (size 4 m x 4 m Approximately) shall be provided on the entrance floor of the building |
| STRAINERS | Stainless steel strainers shall have minimum 1 mm thick screen with 3 mm perforations. Strainers shall be provided with flanges |
| AIR VESSEL | Air vessel shall be provided on top of each riser and shall be fabricated out of 8 mm thick M.S. Sheet. The ends shall be dished. This shall be of 250 mm diameter, 1.2 meter high and installed vertically on suitable legs. The legs shall be provided with M.S. Plate of size 75 mm x 75 mm x 5 mm at the bottom so that the legs do not puncture the roof. |
| The legs shall be grouted in CC foundation. Flange connection shall be provided for connection with wet riser pipe. | |
| Air release valve and pressure gauge with shut off valve shall be provided. The air vessel shall be tested at 25 kgf/cm2 pressure before installation. | |
| SLEEVE | Pipe sleeves of diameter larger than the pipe by least 50 mm shall be provided wherever pipes pass through walls and the annular spaces shall be filled with felt and finished with retaining rings. |
| The space in the floor cut outs around the pipe work shall be closed using cement concrete (1:2:4 mix) or steel sheet, from the fire safety considerations, taking care to see that a small annular space is left around the pipes to prevent transmission of vibration to the structure. | |
| LANDING VALVE | The landing valves shall be as per IS: 5290 |
| The water discharge shall be not less than 900 lpm for single head valves at 7 kgf/cm2 pressure. | |
| The inlet valve shall be at 900 mm above floor level. | |
| FIRST AID HOSE REEL | It shall consist of 20 mm (nominal internal) diameter hose tubing length wrapped around a reel with water inlet pipe, stop valve and shut-off nozzle. The entire assembly is mounted on a wall bracket and can swing 180 degrees. The water inlet shall be connected directly to the riser/down-comer mains by means of 37 mm socket and valve. |
| First aid hose reel shall be as per IS-884. The coupling, branch pipe and nozzle shall be as per IS:8090. | |
| The water flow rate shall be not less than 24 lpm and the range of jet shall be not less than 6 m. | |
| The length of hose tube shall be such that the nozzle of the hose can be taken into every room and within a range of 6 meter from any part of the room. | |
| BRANCH PIPE AND NOZZLES:- | Delivery Hose Couplings Sizes:- These are available in two sizes i.e. 63 mm and 70 mm. Normally size 63 mm is used |
| Branch Pipe and Nozzle | The size of other end i.e. nozzle shall be 20 mm (nominal internal diameter). |
| HOSE PIPES | Hose pipes shall be rubber lined woven jacketed and 63 mm in diameter. They shall conform to Type A ( Re-inforced rubber lined ) of IS: 636. They shall be flexible and capable of being rolled. Length of hose pipe will be 15 meter. |
| AUTOMATIC SPRINKLER SYSTEM | Pressure in the sprinkler installation piping shall not exceed 7 bar and pressure at the most remote sprinkler at any level shall not be less than 0.5 bar and also not more than 5 bar. |
| Sprinkler Protection: | (a) Areas, rooms or places where the water discharged from a sprinkler may pose a fire or explosion or toxic hazard. In such areas alternative arrangement shall be made. |
| (b) Stairs, spaces below stair headings (but not rooms above a stair) and lift wells. Any part of the building not provided with sprinkler protection shall be fire separated by walls. Fire doors not less than 1 hour in fire resistance shall be provided in the opening of such walls. | |
| (c) Wash rooms, toilets and WCs (but not cloak rooms) of area less than 5m2. If area of these rooms exceed 5m2, these shall be provided with sprinkler protection unless fire separated by walls and all openings in the walls are protected. | |
| (d) Sprinklers shall not be required in electrical equipment rooms where all of the following conditions are met: | |
| i) The room is dedicated to electrical equipment only. | |
| ii) Only dry-type electrical equipment is used. | |
| iii) Equipment is installed in a 120 minutes fire-rated enclosure including protection for penetration in walls. | |
| iv) Cable coating is done in trays or trenches to prevent flame spread. | |
| v) Storage is not permitted in the room. | |
| Rooms like server room or electrical control room where alternate protection by other automatic extinguishing systems, (for example gas, powder and water spray). | |
| (f) In areas having height 17 m or above such as in atria, sprinkler installations may be rendered ineffective and hence may be avoided. | |
| Drain Valve | For drainage of system, drain valve 50 mm diameter shall be provided down stream of Installation Control Valve or any subsidiary stop valve. |
| TESTING | All piping shall be tested to hydrostatic test pressure of at least 1.5 times the maximum operating pressure, but not less than 10 kg/sq.cm for a period not less than 24 hours. |
| After completion of the entire work, pressure testing of entire pipe work shall be carried out for 24 hrs. at a pressure of 7.5 kgf/cm2. The drop of pressure up to 0.5 kgf/cm2 shall be accepted. | |
| While Hydro Testing, inclusion of cut-off valves in the mains to be tested can be avoided. All leaks and defects in joints revealed during the testing shall be rectified. | |
| MOTOR STARTER | Starter for the motor shall be direct on line (D.O.L) for motors up to and including 7.5 H.P. rating and automatic star-delta type for motors of higher ratings unless otherwise specified in the tender specifications. However, for main Fire Pump & Sprinkler Pump Soft Starters may be used. |
| Each starter shall be provided with the following protections: – | |
| (a) Thermal overload on all the three phases with adjustable settings, | |
| (b) Independent single phase preventer. (Current sensing type). | |
| (iv) Adequate number of extra NO/NC contacts for interlocks, indicating lamps, remote operation etc. shall be provided on the starter/ contactor. | |
| (v) Under voltage/No volt trip shall not be provided. | |
| SWITCH BOARDS | The board shall be fabricated from 2.0 mm thick CRCA sheet and powder coated after 7 tank treatment process. The board shall be fabricated with IP 42 degree of protection. |
| Switch fuse units shall be used up to and including 32 A and SDFU shall be used for 63 A and above. ACB shall be used for 630 A and above ratings. (iv) All Switch fuse units/SDFUs shall be of AC 23 duty as per IS: 4064-1978 as amended up to date. They shall be complete with suitable HRC cartridge type fuses. |
|
JIGNESH PARMAR
Recent Comments